These 883-511 Piston Bumper are a critical component of the Nailer, it is important to use a genuine Metabo HPT replacement part to ensure proper operation and performance. These 883-511 Piston Bumpers are made of a durable material that can withstand the heavy use of a framing Nailer. Also designed to absorb the shock of the piston when it fires, which helps to protect the Nailer from damage. If you are experiencing problems with your framing Nailer, such as misfires or jams, it is possible that the Piston Bumpers are damaged or worn out. The user should inspect the Piston Bumper for any signs of damage, such as cracks or breaks. If you find any damage, you should replace the Piston Bumper with a genuine Metabo HPT replacement part. Compatible with models; NR83AA3, NV83A2, NV85AG, NR83A2S, 83AA2, NR83A, NR83AA2, NV83A3, NV83A4, NR83A3S, NR83A3, NR83AA4, NR83A2, NR83A5, NR83A5, NR83A5M, NR83AA5M, NV83A5M, NR83A2, NR83A5 and NR83AA5 (sold separately). Please reference the tool manual before purchasing to ensure the proper fit, care, and use.