A clutch that is engaged/disengaged via hydraulic fluid instead of a cable uses a Clutch Master and Clutch Slave Cylinder. When depressing the clutch pedal a lever is squeezed, forcing hydraulic fluid through hydraulic lines to a "slave cylinder" which houses a piston. The piston forces a push rod to engage or disengage the clutch. A clutch master cylinder that contains the hydraulic fluid sits on a support har near the clutch lever. When either the Master or Slave Cylinder fail the clutch is unable to be disengaged.

Fits:
Porsche 911 1987-89
Porsche 930 with G50/50 GearBox