The figure exhibits the vacuum clutch mechanism. Such a clutch utilizes the present vacuum while in the motor manifold to function the clutch. The vacuum clutch is made of a reservoir, non-return valve, vacuum cylinder with piston, and solenoid valve.  To know how a clutch is effective, it helps to https://daltonrcjqw.blogsidea.com/39398803/clutch-kereta-fundamentals-explained