This is an authentic Grip-Rite replacement part. The wave washer is found in a Grip-Rite nailer. This part is made of metal, and is placed in the machine to help cushion the impact of the rod against the gun body. The washer is slightly convex for this purpose. You may require a screwdriver when replacing this part. It is advisable w...Read morehen removing multiple parts to keep careful track of their order so they can be reassembled correctly. This item is sold individually.