HIGH EFFICIENCY: The end is machined with a full radius to prevent damage to the top of the piston. Very easy to use and very practical when doing your own saw or other 2-stroke work. CLUTCH REMOVAL TOOL: This is a general piston stop that requires the crankshaft to be held in place. SCOPE OF APPLICATION: Can be used to hold the clutch or remove the flywheel nut, or to repair power brushes and leaf blowers. EASY TO REMOVE: Simply remove the spark plug, screw on the tool, and gently tighten. Remove the spark plug, screw the tool into place, and lightly press it down. EASY TO USE: Rotate the engine clockwise or counterclockwise until it appears that the piston is in conflict with the tool and is ready to be repaired. Note that most chainsaws have left-hand threads on the clutch side. Quantity delivered: 1 set