Replace: 66785 66786 Top Quality: The piston ring filer are made from high-quality aluminum, and it is durable and long – lasting to use Function: To assure proper piston ring end-gap, the piston ring filer enables the user to file piston rings quickly and accurately How to use: Fix the piston ring on the pin, shake the handle and file the piston ring with grinding wheel to ensure the correct clearance of the piston ring Package Included: 1 * piston ring filer 1* Grinding wheel .