Superior Parts SP 878-303G Aftermarket Piston Bumper for Hitachi NR83A, NR83A2, NR83A2(S) - 883-511, 878649, 877376 (Green) (5/Pack) Pack of 5 Green color Piston Bumper Aftermarket Piston Bumper for Hitachi NR83A, NR83A2, NR83A2(S) - 883-511, 878649, 877376 Precision machined, virgin high density green color plastic framer bumper. (Pack of 5).