Hitachi Replacement Part 883-511 Air Nailer Piston Bumper (4 Pack) Genuine Hitachi Replacement Part For Use With Hitachi NR83A2, NR83A3, NR83AA3, NR83A, and NV83A2 Power Tools 2.5 Inches Long (6.35cm) (4) 883-511 Replacement Piston Bumpers