As the saying goes, "Use the right tool for the job." This red-anodized aluminum Locking Tool screws into the glow plug socket on your gas R/C engine, effectively holding your piston and crankshaft in place. Removing the clutch, clutch nut, and flywheel is now a simple operation. EXI's  Piston Locking Tool allows you to get a nice snug fit for these parts when replacing them.