Get your nailer/stapler back in working order with Captain O-Ring's replacement 876-174 Piston O-Rings. The 876-174 piston o-ring is compatible with Hitachi N3824A, N5008A1, N5008AC, N5008AC2, N5008ACP, N5010A, N5021A, N5024A, N5024A2, NH451, NT50A, NT65A, NT65A2, NT65A3, NV45AA Heavy Duty Coil Nailer, NV45AB 1-3/4" Roofing Coil Nailer, NV45AB2 Side Load Coil Roofing Nailer, NV45AB2(S) Bottom Load Coil Roofing Nailer, NV45AE 1-3/4" Side Load Coil Roofing Nailer, NV50AP2 Full Round Head Nailer, NV50A1 Light Duty Coil Utility Nailer, and NV50AA Light Duty Coil Utility Nailer, and VH501 nailers/staplers. Confirm your model matches one of the above or check your nailer or stapler's manual/parts diagram to confirm it calls for o-ring part number 876-174 before ordering to ensure you receive the correct o-ring. These are the exact OEM match o-rings (Japanese standard size), rather than the similar (but not exact) size that many other retailers offer. They will install right into your nailer or stapler, replacing your old, worn o-ring and function just like when it was new, without catching or causing jams (a common issue for incorrect size o-rings). This piston o-ring is usually the first to wear out with regular use of your nail/staple gun and is an easy fix to replace this o-ring and get it back up and running again. Package contains twelve (12) O-Rings. Manufactured and warrantied by Captain O-Ring LLC. Proudly assembled in the USA!