Part Number: 885-667. Package Includes: as images show, 885-667 Aftermarket Piston Driver 1 pcs. Compatible With: Hitachi NT65M2 885667 Driver Assembly Nailer Gun. Aerospace grade number 2024 Aluminum piston, Heat treated tool steel 6150 Rockwell hardness 50-52. These parts install quickly to make your Framing nailer work like new again. A brand-new, unused, unopened, undamaged item in its original packaging. Return refund: If you have any questions, you can refund in full without any problems