CMC Triggers Enhanced Bolt Carrier Group was designed for shooters who demand superior performance weapon components in the heart of their firearm. CMC proudly manufactures the highest quality firearms components in the industry. Features: Black Nitride finish Enlarged forward ports Optimized for suppressor use Hardened 4340 cam pin Mil-Spec 8740 steel firing pin MPI and HPT tested Mil-Spec Extractor Spring & O-Ring .308 and 6.5 Creedmoor compatible