Model: SP-P1 Package Includes: SP 875-643 Compression Spring, SP 874-436 Aftermarket O-Ring, SP 884-113 Aftermarket Trigger Plunger (SP 877-338), SP 875-638 Aftermarket O-Ring, SP 877-337 Aftermarket Trigger Valve Stem, SP 877-339 Aftermarket Plunger (B). For Hitachi NR83A NR83A2 NR83A2(S) NR83A3 The plunger valve is made of high-strength materials and precision technology, with excellent wear resistance, corrosion resistance, and compressive strength The design fully follows the original factory specifications, with precise accessory interfaces and a simple and clear installation process