S&W M&P 9/40 Sear Housing Block Mag Safety | OEM 421970000 Fire Control Parts Each may have slightly different

Each may have slightly different internal parts

1076) were adopted by the FBI and other agencies

Inconsistent cylinder timing or alignment with barrel

The oversize hand is a slightly larger version of the standard hand

S&W M&P 9/40 Sear Housing Block Mag Safety | OEM 421970000 Fire Control Parts Each may have slightly differentSmith & Wesson OEM Sear Housing Block Assembly for M&P 9 40 Pistols with Magazine Safety This factory sear housing block assembly with integrated magazine safety is a critical fire control component for M&P9 and M&P40 pistols equipped with magazine disconnect safety. Genuine S&W quality ensures proper fit, reliable function, and safe operation. Genuine S&W Part: Factory OEM component (Part #421970000) Multi Caliber Fit: Compatible with M&P 9mm and .