The Bullet Proof Hammer Strut has been designed to be the proper length and shape for the ideal 1911 trigger job. EDM machined from hardened steel plate, this replacement part prevents interference with the sear spring and grip safety which could disrupt a fine trigger job. The strut is also slightly longer than a stock part with beveled bottom edges for a smoother feel during cycling. Mfg: Wilson Combat SPECS: 681B is EDM machined from hardened blued A-2 tool steel. 681S is EDM machined from hardened 17-4 PH stainless steel.