Cryptic 6.5mm Grendel/7.62x39mm Bolt Carrier Group (BCG) - Complete

Cryptic 6.5mm Grendel/7.62x39mm Bolt Carrier Group (BCG) - Complete\n\n- Coated Bolt Carrier Group BCG (full auto version) for AR15, M16, or M4 machined from Mil-Spec 8620 aircraft quality steel with shrouded firing pin and Mil-Spec chrome lined interior.\n- BCG includes the proper chrome lined and heat treated gas key. Gas key is secured to carrier with Grade 8 fasteners and properly staked per Mil-Specs.\n- The bolt assembly is CNC machined from Mil-Spec Carpenter No. 158 steel and shot peened for increased strength per Mil-Spec.\n- HPT (High Pressure Batch Tested) and MPI (Magnetic Particle Inspected).\n\nPackage Contents:\n- Cryptic 6.5mm Grendel/7.62x39mm Bolt Carrier Group - Complete\n- Gas Key, Key Staked with Grade 8 Screws\n- Bolt w/ Spring and Ejector\n- Extractor w/ Spring and viton O-ring\n- Firing Pin\n- Cam Pin\n\nWhat firearm models is this compatible with?\n- AR-15, M4, M16\n\nSpecifications:\n- Manufacturer: Cryptic\n- Fabric/Material: Carpenter 158 Steel, 8620 Aircraft Quality Steel\n- Carrier Material: 8620 Steel\n- Bolt Material: Steel\n- Caliber: 6.5mm Grendel, 7.62x39mm\n- Gun Make: AR Platform\n- Gun Model: M16, M4, AR-15\n- Hand: Ambidextrous\n- Weight: 11.55 oz\n- Included Accessories: Standard\n\nFinish and color options vary by model: Magnese Phosphate, Black Nitride, Nickel Boron, Mystic Midnight, Mystic Black, Mystic Gold, Mystic Bronze, Mystic Silver.