AR-9 build to the next level with the KAK Industry 9mm Enhanced Bolt Carrier Group engineered for reliability, smooth cycling and long-lasting performance. Whether you're running a dedicated 9mm AR this high-quality BCG ensures flawless operation. Compatible with Glock or Colt style magazines for versatile magazine compatibility Made from high-quality 8620 steel for superior strength and durability Gas key precision-machined from 4130 billet steel, expertly staked for secure and reliable performance Extractor M16, fully machined and phosphate-coated for enhanced durability and reliable extraction performance Carrier finish nitride for improved wear resistance and corrosion protection Firing pin 8740 steel, properly heat-treated and chrome-plated for enhanced durability and corrosion-resistance