It is a type of transmission used in automotive applications. It generally utilizes a driver-operated clutch operated by a pedal or lever, for regulating torque transfer from the engine to the transmission, and a gear-shift either operated by hand (as in a car) or by foot (as on a motorcycle). A manual transmission has several shafts with various gears and other components attached to them. Typically, a rear-wheel-drive transmission has three shafts: an input shaft, a countershaft and an output shaft. Clutch is a coupling device is used to separate the engine and transmission when necessary. Without it, the engine and tires would at all times be inextricably linked, and any time the vehicle stopped the engine would stall. Without the clutch, changing gears would be very difficult, even with the vehicle moving already: deselecting a gear while the transmission is under load requires considerable force. In a car the clutch is usually operated by a pedal; on a motorcycle, a lever on the left handlebar serves the purpose.