Precision CNC machined from 316 stainless steel bar stock, the Bullet-Proof Recoil Spring Plug by Wilson Combat is engineered for maximum durability, hence the name "Bullet Proof". The end of the plug features concentric rings for a sleek look that the bushing / bushing wrench will not mar during assembly and/or disassembly These 1911 parts meet or exceed original factory specifications. If you're building a gun, or wish to bring your 1911 back to true mil-spec, these parts will provide exceptional service. May require fitting to specific gun. This recoil plug is .030" long for use with the Bullet Proof barrel bushing (product #535136)