Cryptic .223/5.56/.300 AAC Blackout Left Hand Bolt Carrier Group (BCG) - Complete

Cryptic .223/5.56/.300 AAC Blackout Left Hand Bolt Carrier Group - Complete. Coated Bolt Carrier Group BCG for AR15, M16, or M4 machined from Mil-Spec 8620 aircraft quality steel with shrouded firing pin and Mil-Spec chrome lined interior. Gas key chrome lined and heat treated, secured to carrier with Grade 8 fasteners and properly staked per Mil-Spec. The bolt assembly is CNC machined from Carpenter 158 steel and shot peened for increased strength per Mil-Spec; includes tool steel extractor with spring and viton O-ring; firing pin chromed; cam pin. HPT (High Pressure Batch Tested) and MPI (Magnetic Particle Inspected). Specifications for Cryptic .223/5.56/.300 AAC Blackout Left Hand Bolt Carrier Group (BCG) - Complete: Finish: Chrome Plated; Fabric/Material: 8620 Aircraft Quality Steel, Carpenter 158 Steel; Carrier Material: 8620 Steel; Bolt Material: Steel; Caliber: 5.56x45mm NATO, .300 AAC Blackout, .223 Remington; Gun Make: AR Platform; Gun Model: M16, M4, AR-15; Hand: Ambidextrous; Weight: 11.55 oz; Condition: New; Included Accessories: Standard. Package Contents: Cryptic .223/5.56/.300 AAC Blackout Left Hand Bolt Carrier Group - Complete; Chrome Lined Gas Key; Key Staked with Grade 8 Screws; Bolt w/ Spring and Ejector; Tool Steel Extractor w/ Spring and viton O-ring; Firing Pin w/ Chrome Finish; Cam Pin; What firearm models does the manufacturer say Cryptic .223/5.56/.300 AAC Blackout Left Hand Bolt Carrier Group (BCG) - Complete is compatible with AR-15, M4, M16.