Slave cylinders are hydraulic components integral to vehicle clutch and brake systems. Located at the wheel or transmission, they convert hydraulic pressure from the master cylinder into mechanical force, actuating either brake calipers or the clutch fork. Internal pistons and seals translate fluid pressure into linear motion, engaging braking or clutch disengagement. Construction typically utilizes metal or polymer bodies with reinforced rubber boots to protect internal components. Variations include internal or external bleed screw designs for air removal during servicing, and bore sizes matched to master cylinder output for optimal performance.