Rennkit

The Fuel Cap Flexible Tether by Rennkit is a replacement retaining strap for compatible Porsche 986, 987 Boxster and Cayman, 996 and 997 models from 1999 onwards. It replaces a snapped or deteriorated tether so that the fuel cap remains attached during refuelling.

Fits:

• Porsche 986 Boxster
• Porsche 987 Boxster
• Porsche 987 Cayman
• Porsche 996
• Porsche 997

What This Product Does

This flexible tether secures the existing fuel filler cap to the vehicle, helping to keep the cap away from painted bodywork while the tank is being filled. It provides a practical alternative to replacing an otherwise serviceable fuel cap solely because its original retaining strap has broken.

Functions

• Retains the fuel cap when it is removed for refuelling
• Replaces a broken, brittle or missing original tether
• Helps prevent the loose cap from resting against painted bodywork
• Allows the existing compatible fuel cap to be retained

Technical Details

• Manufacturer: Rennkit
• Product type: flexible replacement fuel cap tether
• Application: compatible Porsche models from 1999 onwards
• Designed for installation on a matching original-style fuel cap
• DIY fitting typically takes approximately ten minutes
• Removal and installation instructions are supplied

Symptoms of Fault

• The original fuel cap tether has split or snapped
• The cap is no longer retained when removed
• The tether has become brittle, cracked or inflexible
• The loose cap must be placed on or near the vehicle during refuelling

Why Replacement Matters

Renewing a damaged tether restores the intended retaining function without replacing the complete cap. It also reduces the chance of the cap being dropped, misplaced or placed directly against the paintwork. Before ordering, compare the fitted cap carefully with the product image to confirm that its design and attachment arrangement match.

FAQs

• Does this include a complete fuel cap?
  No. This product is a replacement flexible tether for a compatible existing cap.
• How long does installation take?
  Installation typically takes about ten minutes and involves removing the damaged tether before fitting the replacement.
• How can I confirm compatibility?
  Check the model and year, then compare the existing fuel cap with the product image and attachment arrangement.
• Why replace only the tether?
  If the cap remains serviceable, replacing the retaining strap restores its convenient attachment without changing the complete cap.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

RK-CT

The product you are viewing cross references to these numbers

The Rennkit MicroModule Spoiler Warning Device is designed for Porsche 996 Turbo and 997 Turbo models fitted with either an operational powered wing or a fixed, non-moving spoiler. Two application-specific versions are available to prevent the spoiler warning associated with the selected wing configuration.

Fits:

• Porsche 996 TURBO 2000-05
• Porsche 997 MK1 TURBO 2007-09
• Porsche 997 MKII Turbo 2010-13

What This Product Does

The MicroModule connects to the vehicle's factory spoiler wiring and manages the warning signal after an eRam installation or fixed-wing conversion. Selecting the correct version allows the warning system to operate appropriately for a functional motorised wing or a static spoiler without a lifting mechanism.

Functions

• Prevents the spoiler warning generated by the applicable wing configuration
• Supports Rennkit eRam systems and other functional wings with a working motor
• Accommodates fixed, integrated or non-functional wings with no movement
• Connects to the existing spoiler wiring
• Provides separate solutions for powered and static installations

Technical Details

• Manufacturer: Rennkit
• Operational Wing version, for eRam kits and functional wings with a working motor
• Fixed Wing version, for non-functional or static wings without movement
• All required connectors are included
• Written installation instructions are supplied

NOTE: Included with every Rennkit eRam Kit.

Symptoms of Fault

• Spoiler warning displayed following a fixed-wing conversion
• Warning remains present after fitting a functional electric wing system
• Factory hydraulic spoiler mechanism has been removed or bypassed
• A static Aerokit, GT-style or aftermarket integrated wing has no powered movement

Why Replacement Matters

The appropriate MicroModule provides a dedicated electrical solution for the chosen rear-wing arrangement. Use EK-MM-OW where the wing remains operational through a working motor or eRam system. Choose EK-MM-FW where the spoiler is fixed and has no lifting movement. Existing mechanical, wiring or motor faults should be diagnosed before fitting the module, as it is intended for correctly configured functional or static-wing installations.

FAQs

• Which version is required for an eRam kit? Select the Operational Wing MicroModule, SKU EK-MM-OW, because the wing retains powered movement.
• Which version suits a permanently fixed spoiler? Select the Fixed Wing MicroModule, SKU EK-MM-FW, for static or non-functional wings without a motorised lifting action.
• Are connectors included? Yes, the necessary connectors and written installation instructions are supplied.
• Will the module repair a faulty spoiler motor? No. Any motor, mechanism, wiring or connector fault should be identified separately before installation.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

EK-MM-

The product you are viewing cross references to these numbers

4.75" eRam Kit™ electric wing system for Porsche 996TT Fitted With 997T Spoiler.
Highest electric wing lift Kit™ possible - Similar height to GT3 and GT4 wings, provides the ultimate Downforce.

Do not risk Pentosin® Power Steering fluid leaks into your engine bay or down the bumper. Extensively designed and engineered to permanently fix the overly complex and troublesome factory hydraulic mechanism. Since 2015, our eRam Kit™ is the best permanent economical solution to maintain a fully functional wing!

The dealer wants up to £1000's to replace a troublesome hydraulic mechanism. Others offer a rebuild service, simply tearing down and repairing the same failure prone mechanism, often using solvents to swell internal o-rings. Another offers shiny aftermarket parts for the internal hydraulic mechanism made from stainless instead of brass. They do not even attempt to call it a permanent solution, claiming it is "easy" to change out cheap internal o-rings to refill and bleed the mechanism when it fails again… Who wants to go through that EVER let alone more than once? It is only a matter of time until hot engine bay conditions destroy one of many hydraulic components that are failure prone!
The eRam Kit™ wing elevator consists of two pre-assembled self-contained electric Rams that simply bolt onto the engine lid with absolutely NO modifications. The eRam Kit™ includes a small electronic "MicroModule Device™" that connects to the factory wiring and prevents the dreaded SPOILER WARNING. Nearly plug and play! WORKS EXACTLY LIKE THE FACTORY MECHANISM.

The patented eRam Kit™ comes with two self-contained electric eRams, all fittings, fasteners, electrical connections, and the tiny MicroModule Device™ which prevents the spoiler warning. No cutting, drilling or modification to any part of the car. Easy install – about the same skill level as changing brake pads. Installation of the eRam Kit™ takes about 2 hours for anyone with any mechanical skill. Most customers install the eRam Kit™ themselves using our illustrated instruction guide and video (sent with purchase). Easily maintained – no special tools needed. Easily modified – for example to exchange for different length rams or to add Dust & Moisture Boots.

Fits:
Porsche 996 Turbo 2001-2005 (Fitted With 997T Spoiler)

Diagram ref no 2 (LEFT) & 3 (RIGHT)

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

EK6-475-7W-S

The product you are viewing cross references to these numbers

Climate control blend door repair kit.

Foam coming out your vents? This is the only way to permanently repair the Hot/Cold blend door and eliminate disintegrating foam. Remove and repair the climate control blend door. Comes with parts and tools necessary with illustrated step-by-step instructions.

This is the fix for the hot and cold blend door only.

Fits:
Porsche 986 Boxster 1997-2004
Porsche 996 Carrera / Turbo / GT3 1999-2004

Bluetooth Retrofit Kit (No phone module) calling and audio streaming 996 / 997.1 / 987 2002-2011 / 986.2 2003-05
For cars WITHOUT factory phone module.

Features:
Keep the factory look – head unit remains in place!
Bluetooth hands-free, A2DP music streaming
Make/Take Calls – Hands Free using provided mic
USB / SD Card Music Playback
Supports up to 64 Gb FAT32 Card
Up to 5 folders with 999 songs in each
Song filename displayed .mp3 and .wma music file supported
Full integration with PCM menu

When used with the PCM 3, CDR24 or CDR30, the car needs to have Porsche CD changer installed.

For the following 2002 – 2011 cars:

Porsche 986.2 Boxster 2003-05
Porsche 987.1 and 987.2 Boxster / Cayman
Porsche 996.2 (911) Carrera / C2 / C4 / Targa / Cabrio / GT3 / Turbo / GT2
Porsche 997.1 (911) Carrera / C2 / C4 / Targa / Cabrio / GT3 / Turbo / GT2


BTR-3 Kit Contents:

Bluetooth Main Unit
Mic Unit and cable
Aux connector cable
FO Connector cable to head unit CD port
FO Connector loop cable for CD Changer
12V Wiring kit

Caliper Cooler Kit for 996 Turbo or Carrera 4S with Larger 350 mm Rotors (not PCCB)

A popular upgrade to the 996 Carrera 4S and Turbo is larger diameter rotors – swapping out stock 330 mm rotors to larger 350 mm rotors like those on the 997 Turbo. This change provides better braking action and feel.
Rennkit™ has the solution: Cal*Cool™ brake caliper coolers. A quick modification that allows excess heat to dissipate much faster. Conductive and convective heat transfer quickly dissipates brake caliper heat while driving. When parked, conductive and radiative heat transfer continue to effectively remove heat from hot calipers. Track tested – all 4 corners remained below 370F:


Porsche 996 TT 2001-04 Rear
Porsche 996 C4S 2001-04 Rear

Fits With:
997 Turbo Rear Disc Part No
99735240502 Rear Left
99735240602 Rear Right

Caliper Cooler Kit for 996 Turbo or Carrera 4S with Larger 350 mm Rotors (not PCCB)

A popular upgrade to the 996 Carrera 4S and Turbo is larger diameter rotors – swapping out stock 330 mm rotors to larger 350 mm rotors like those on the 997 Turbo. This change provides better braking action and feel.
Rennkit™ has the solution: Cal*Cool™ brake caliper coolers. A quick modification that allows excess heat to dissipate much faster. Conductive and convective heat transfer quickly dissipates brake caliper heat while driving. When parked, conductive and radiative heat transfer continue to effectively remove heat from hot calipers. Track tested – all 4 corners remained below 370F:


Porsche 996 TT 2001-04 Front
Porsche 996 C4S 2001-04 Front

Fits With:
997 Turbo Front Disc Part No
99735140501 Front Left
99735140601 Front Right

4.8" eRam Kit™ electric wing system for 997 Turbo
Similar height to GT3 and GT4 wings, provides Superior Downforce.

Do not risk Pentosin® Power Steering fluid leaks into your engine bay or down the bumper. Extensively designed and engineered to permanently fix the overly complex and troublesome factory hydraulic mechanism. Since 2015, our eRam Kit™ is the best permanent economical solution to maintain a fully functional wing!

The dealer wants up to £1000's to replace a troublesome hydraulic mechanism. Others offer a rebuild service, simply tearing down and repairing the same failure prone mechanism, often using solvents to swell internal o-rings. Another offers shiny aftermarket parts for the internal hydraulic mechanism made from stainless instead of brass. They do not even attempt to call it a permanent solution, claiming it is "easy" to change out cheap internal o-rings to refill and bleed the mechanism when it fails again… Who wants to go through that EVER let alone more than once? It is only a matter of time until hot engine bay conditions destroy one of many hydraulic components that are failure prone!
The eRam Kit™ wing elevator consists of two pre-assembled self-contained electric Rams that simply bolt onto the engine lid with absolutely NO modifications. The eRam Kit™ includes a small electronic "MicroModule Device™" that connects to the factory wiring and prevents the dreaded SPOILER WARNING. Nearly plug and play! WORKS EXACTLY LIKE THE FACTORY MECHANISM.

The patented eRam Kit™ comes with two self-contained electric eRams, all fittings, fasteners, electrical connections, and the tiny MicroModule Device™ which prevents the spoiler warning. No cutting, drilling or modification to any part of the car. Easy install – about the same skill level as changing brake pads. Installation of the eRam Kit™ takes about 2 hours for anyone with any mechanical skill. Most customers install the eRam Kit™ themselves using our illustrated instruction guide and video (sent with purchase). Easily maintained – no special tools needed. Easily modified – for example to exchange for different length rams or to add Dust & Moisture Boots.

Fits:
Porsche 997 Turbo

Click 'Zoom in' for large parts diagram.
Diagram ref no 2 (LEFT) & 3 (RIGHT)

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

EK7-4.8-S

The product you are viewing cross references to these numbers

4" eRam Kit™ electric wing system for 997 Turbo
Creates very excellent downforce, wing looks great when up.

Do not risk Pentosin® Power Steering fluid leaks into your engine bay or down the bumper. Extensively designed and engineered to permanently fix the overly complex and troublesome factory hydraulic mechanism. Since 2015, our eRam Kit™ is the best permanent economical solution to maintain a fully functional wing!

The dealer wants up to £1000's to replace a troublesome hydraulic mechanism. Others offer a rebuild service, simply tearing down and repairing the same failure prone mechanism, often using solvents to swell internal o-rings. Another offers shiny aftermarket parts for the internal hydraulic mechanism made from stainless instead of brass. They do not even attempt to call it a permanent solution, claiming it is "easy" to change out cheap internal o-rings to refill and bleed the mechanism when it fails again… Who wants to go through that EVER let alone more than once? It is only a matter of time until hot engine bay conditions destroy one of many hydraulic components that are failure prone!
The eRam Kit™ wing elevator consists of two pre-assembled self-contained electric Rams that simply bolt onto the engine lid with absolutely NO modifications. The eRam Kit™ includes a small electronic "MicroModule Device™" that connects to the factory wiring and prevents the dreaded SPOILER WARNING. Nearly plug and play! WORKS EXACTLY LIKE THE FACTORY MECHANISM.

The patented eRam Kit™ comes with two self-contained electric eRams, all fittings, fasteners, electrical connections, and the tiny MicroModule Device™ which prevents the spoiler warning. No cutting, drilling or modification to any part of the car. Easy install – about the same skill level as changing brake pads. Installation of the eRam Kit™ takes about 2 hours for anyone with any mechanical skill. Most customers install the eRam Kit™ themselves using our illustrated instruction guide and video (sent with purchase). Easily maintained – no special tools needed. Easily modified – for example to exchange for different length rams or to add Dust & Moisture Boots.

Fits:
Porsche 997 Turbo

Diagram ref no 2 (LEFT) & 3 (RIGHT)

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

EK7-4-S

The product you are viewing cross references to these numbers

3" eRam Kit™ electric wing system for 997 Turbo
Closest height version for Cabriolet

Do not risk Pentosin® Power Steering fluid leaks into your engine bay or down the bumper. Extensively designed and engineered to permanently fix the overly complex and troublesome factory hydraulic mechanism. Since 2015, our eRam Kit™ is the best permanent economical solution to maintain a fully functional wing!

The dealer wants up to £1000's to replace a troublesome hydraulic mechanism. Others offer a rebuild service, simply tearing down and repairing the same failure prone mechanism, often using solvents to swell internal o-rings. Another offers shiny aftermarket parts for the internal hydraulic mechanism made from stainless instead of brass. They do not even attempt to call it a permanent solution, claiming it is "easy" to change out cheap internal o-rings to refill and bleed the mechanism when it fails again… Who wants to go through that EVER let alone more than once? It is only a matter of time until hot engine bay conditions destroy one of many hydraulic components that are failure prone!
The eRam Kit™ wing elevator consists of two pre-assembled self-contained electric Rams that simply bolt onto the engine lid with absolutely NO modifications. The eRam Kit™ includes a small electronic "MicroModule Device™" that connects to the factory wiring and prevents the dreaded SPOILER WARNING. Nearly plug and play! WORKS EXACTLY LIKE THE FACTORY MECHANISM.

The patented eRam Kit™ comes with two self-contained electric eRams, all fittings, fasteners, electrical connections, and the tiny MicroModule Device™ which prevents the spoiler warning. No cutting, drilling or modification to any part of the car. Easy install – about the same skill level as changing brake pads. Installation of the eRam Kit™ takes about 2 hours for anyone with any mechanical skill. Most customers install the eRam Kit™ themselves using our illustrated instruction guide and video (sent with purchase). Easily maintained – no special tools needed. Easily modified – for example to exchange for different length rams or to add Dust & Moisture Boots.

Fits:
Porsche 997 Turbo

Diagram ref no 2 (LEFT) & 3 (RIGHT)

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

EK7-3-S

The product you are viewing cross references to these numbers

Bluetooth Retrofit Kit calling and audio streaming 996 / 986 Boxster

For 996.1 (911) MK I Turbo – Carrera – C4S – C4 – Targa and 986.1 MK I Boxster era vehicles. The idea is simple, include EVERYTHING in a kit to make the installation DIY simple and provide functionality of streaming Bluetooth while charging your smart phone. No cords or chargers – always on! For 1997 – 2002 era factory head units. Perfect for enthusiasts who don't want to add an aftermarket head unit to stream Bluetooth – this kit retains the factory look.

Features:

Keep your factory look!
Stream music from your smart phone
Make/Take Calls – Hands Free
Separate cable to charge your smart phone
Noise Isolator – ensures quieter, static free operation
Includes Power Converter – no need to plug into cigarette lighter or recharge battery – the Bluetooth receiver is ALWAYS POWERED – ALWAYS ON

For the following head units:

Becker Traffic Pro, Mexico CD (7803, CC4325, CC4327, CD4337, CC4370)
Becker CR-22, CDR-22, CR-220, CDR-220
Becker CDR-210, CR-210 and PCM1 radios with CD Changer port

NOTE: Does NOT work with the "MOST "fiber optic units, like CDR-23 found in 2003 onward vehicles. Remote CD player is inoperable. For CR/CDR 210 head units; this device will not work unless unless there is a factory CD Changer in the front trunk.

INSTALLATION INSTRUCTIONS

Rear spoiler 1" wing extenders. Porsche 987 Cayman

Wing Extenders raise the factory or aftermarket wing an additional 1" (25.4 mm) for a more aggressive look on the Cayman. The Wing Extenders help improve downforce and integrate with the factory shafts perfectly. Same satin look – seamless extensions. All hardware and detailed illustrated installation instructions included. Also works with any aftermarket wing that bolts to the factory shafts!

Fits:
Porsche 987 Cayman

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

987WE-1

The product you are viewing cross references to these numbers

2" eRam Kit™ electric wing system for 997 Turbo
Up/Down Speed of 5 sec
NOT RECOMMENDED FOR CABRIO

Do not risk Pentosin® Power Steering fluid leaks into your engine bay or down the bumper. Extensively designed and engineered to permanently fix the overly complex and troublesome factory hydraulic mechanism. Since 2015, our eRam Kit™ is the best permanent economical solution to maintain a fully functional wing!

The dealer wants up to £1000's to replace a troublesome hydraulic mechanism. Others offer a rebuild service, simply tearing down and repairing the same failure prone mechanism, often using solvents to swell internal o-rings. Another offers shiny aftermarket parts for the internal hydraulic mechanism made from stainless instead of brass. They do not even attempt to call it a permanent solution, claiming it is "easy" to change out cheap internal o-rings to refill and bleed the mechanism when it fails again… Who wants to go through that EVER let alone more than once? It is only a matter of time until hot engine bay conditions destroy one of many hydraulic components that are failure prone!
The eRam Kit™ wing elevator consists of two pre-assembled self-contained electric Rams that simply bolt onto the engine lid with absolutely NO modifications. The eRam Kit™ includes a small electronic "MicroModule Device™" that connects to the factory wiring and prevents the dreaded SPOILER WARNING. Nearly plug and play! WORKS EXACTLY LIKE THE FACTORY MECHANISM.

The patented eRam Kit™ comes with two self-contained electric eRams, all fittings, fasteners, electrical connections, and the tiny MicroModule Device™ which prevents the spoiler warning. No cutting, drilling or modification to any part of the car. Easy install – about the same skill level as changing brake pads. Installation of the eRam Kit™ takes about 2 hours for anyone with any mechanical skill. Most customers install the eRam Kit™ themselves using our illustrated instruction guide and video (sent with purchase). Easily maintained – no special tools needed. Easily modified – for example to exchange for different length rams or to add Dust & Moisture Boots.

Fits:
Porsche 997 Turbo

Diagram ref no 2 (LEFT) & 3 (RIGHT)

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

EK7-2-SS

The product you are viewing cross references to these numbers

4.75" eRam Kit™ electric wing system for 996 Turbo
Highest electric wing lift Kit™ possible - Similar height to GT3 and GT4 wings, provides the ultimate Downforce.

Do not risk Pentosin® Power Steering fluid leaks into your engine bay or down the bumper. Extensively designed and engineered to permanently fix the overly complex and troublesome factory hydraulic mechanism. Since 2015, our eRam Kit™ is the best permanent economical solution to maintain a fully functional wing!

The dealer wants up to £1000's to replace a troublesome hydraulic mechanism. Others offer a rebuild service, simply tearing down and repairing the same failure prone mechanism, often using solvents to swell internal o-rings. Another offers shiny aftermarket parts for the internal hydraulic mechanism made from stainless instead of brass. They do not even attempt to call it a permanent solution, claiming it is "easy" to change out cheap internal o-rings to refill and bleed the mechanism when it fails again… Who wants to go through that EVER let alone more than once? It is only a matter of time until hot engine bay conditions destroy one of many hydraulic components that are failure prone!
The eRam Kit™ wing elevator consists of two pre-assembled self-contained electric Rams that simply bolt onto the engine lid with absolutely NO modifications. The eRam Kit™ includes a small electronic "MicroModule Device™" that connects to the factory wiring and prevents the dreaded SPOILER WARNING. Nearly plug and play! WORKS EXACTLY LIKE THE FACTORY MECHANISM.

The patented eRam Kit™ comes with two self-contained electric eRams, all fittings, fasteners, electrical connections, and the tiny MicroModule Device™ which prevents the spoiler warning. No cutting, drilling or modification to any part of the car. Easy install – about the same skill level as changing brake pads. Installation of the eRam Kit™ takes about 2 hours for anyone with any mechanical skill. Most customers install the eRam Kit™ themselves using our illustrated instruction guide and video (sent with purchase). Easily maintained – no special tools needed. Easily modified – for example to exchange for different length rams or to add Dust & Moisture Boots.

Fits:
Porsche 996 Turbo 2001-2005

Diagram ref no 2 (LEFT) & 3 (RIGHT)

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

EK6-475-S

The product you are viewing cross references to these numbers

4" eRam Kit™ electric wing system for 996 Turbo
Fast version that creates very good downforce, wing looks great when up.

Do not risk Pentosin® Power Steering fluid leaks into your engine bay or down the bumper. Extensively designed and engineered to permanently fix the overly complex and troublesome factory hydraulic mechanism. Since 2015, our eRam Kit™ is the best permanent economical solution to maintain a fully functional wing!

The dealer wants up to £1000's to replace a troublesome hydraulic mechanism. Others offer a rebuild service, simply tearing down and repairing the same failure prone mechanism, often using solvents to swell internal o-rings. Another offers shiny aftermarket parts for the internal hydraulic mechanism made from stainless instead of brass. They do not even attempt to call it a permanent solution, claiming it is "easy" to change out cheap internal o-rings to refill and bleed the mechanism when it fails again… Who wants to go through that EVER let alone more than once? It is only a matter of time until hot engine bay conditions destroy one of many hydraulic components that are failure prone!
The eRam Kit™ wing elevator consists of two pre-assembled self-contained electric Rams that simply bolt onto the engine lid with absolutely NO modifications. The eRam Kit™ includes a small electronic "MicroModule Device™" that connects to the factory wiring and prevents the dreaded SPOILER WARNING. Nearly plug and play! WORKS EXACTLY LIKE THE FACTORY MECHANISM.

The patented eRam Kit™ comes with two self-contained electric eRams, all fittings, fasteners, electrical connections, and the tiny MicroModule Device™ which prevents the spoiler warning. No cutting, drilling or modification to any part of the car. Easy install – about the same skill level as changing brake pads. Installation of the eRam Kit™ takes about 2 hours for anyone with any mechanical skill. Most customers install the eRam Kit™ themselves using our illustrated instruction guide and video (sent with purchase). Easily maintained – no special tools needed. Easily modified – for example to exchange for different length rams or to add Dust & Moisture Boots.

Fits:
Porsche 996 Turbo 2001-2005

Diagram ref no 2 (LEFT) & 3 (RIGHT)

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

EK6-4-S

The product you are viewing cross references to these numbers