Product Description Machined from 4140" Nitride Coating, MIL-SPEC configuration, Staked MIL-SPEC Gas Key, M16 Style.Features :Nitride CoatingMachined from 4140M16 Style Bootleg 5.56 Nitride Bcg Complete at United States Association of Gun Owners $117.97 Buy Now Check Price on Amazon Check Price on eBay