Porter Cable 886113 Piston Bumper. Piston bumper is used on nailer. This part fits model number RN175. This piston bumper also used on a stapler. 5-Inch long, 5-Inch wide, and 4-Inch high. Package weight of this item is 4-Pound. Porter-Cable is a brand with a proud history of innovation and has brought many firsts to the power tool industry. The company designs, manufactures and distributes electric and cordless power tools, pneumatic tools and compressors, pressure washers, generators and related accessories for the professional woodworking, commercial/residential construction, plumbing and electrical markets.