This is an enhanced version of my standard piston un-sticking device. It comes with both a shrader valve and a grease fitting , also included is a pressure gauge that will read up to 1000psi. This allows you to pressurize a stuck cylinder with compressed air after a small amount of penetrating oil has been added to the cylinder. If this approach is not successful in causing the piston to move, then the cylinder can be filled with ATF and the device reinstalled with the grease fitting option, with the use of a grease gun a significant amount of force can be applied to unstick the piston. Keep in mind that too much pressure could rupture the cylinder, hence the need for the gauge. What the maximum allowable force would be is unknown for your particular situation. You will have to provide your own seal borrowed from a discarded spark plug.