Our upgraded nickel boron bolt carrier group is an eye catching addition to your AR build. Mil-spec dimensions and coating ensure the highest quality and correct component interface.Features:No Aero 'A' LogoMachined from 8620 Tool Steel (Carrier) and 9310 Steel (Bolt)Carrier has forward assist serrationsShrouded firing pinNickel Boron Coating inside and out (Bolt, Carrier, and Gas Key)Forged Mil-Spec gas key attached with Grade 8 hardware and Properly staked.5.56 Bolt is shot Peened and MPIMil-Spec Extractor Spring, black extractor insert, Viton O-RingTool Steel ExtractorHigh quality BCG