Quantity: 1 x Piston Bumper, 1 x Bumper Sheet. Replacement model parts: 878-179 877-993 Compatible with Hitachi NV45AB2, NH451, NV45AB2(S), Applicable to: NT50A, NV45AE, NV45AA, NV50A1, NV45AB, NV50AP, NV50AP2, VH501, N5008A1.