Part Number: 877-307. Package Includes: as images show, Components include: 884-110 Exhaust valve, 877-854 Gasket, 877-307 Head cap and washer set. Compatible with: Hitachi NR83A NR83A2 NR83A2(S) Framing Nailer Part. handy kit makes an overhaul repair of your NR83 framing nail gun fast & easy. These parts install quickly to make your nailer work like new again. A brand-new, unused, unopened, undamaged item in its original packaging.