Aftermarket O-Ring Kit Fits Hitachi NV45AA,NV45AB,NV45AB2,NV45AC,NV45AE and NV45AB2(S) Nailers. This Kit consists pack of 2 for each of the 15 O-Rings listed below: 872-645(NV45, NV83 and NT65) 872-821(NV45) 876-161(NV45 and NT65) 876-167(NV45 and NT65) 877-123(NV45 and NT65) 877-124(NV45 and NT65) 877-125(NV45) 877-126(NV45 and NT65) 877-763(NV45, NR90 and NT65) 877-764(NV45) 884-112(NV45,NV83 and NT65) 885-793(NV45) 875-638(NR83 and NV45) 876-174(NV45 and NT65) 874-820(NV45 and NR83)