The RISE Armament Rifle Bolt Carrier Group BCG ensures the highest level of performance out of your favorite rifle. These Bolt Carrier Groups by RISE Armament reduce friction and increase the smoothness of each shot with high-quality steel parts, a heat-treated carrier, and a Grade 8 hardened gas key. The RISE Armament AR-15/M-16 BCG is individually MPI tested for quality so you can be confident you're getting an overall improved performance. Choose the RISE Armament Advanced Bolt Carrier Group BCG for a great new addition to your rifle. Specifications for RISE Armament AR-15 Bolt Carrier Group (BCG): Manufacturer: RISE Armament Fabric/Material: 9310 Steel, 8620 Steel Caliber: .223 Remington, 5.56x45mm NATO Gun Make: AR Platform Gun Model: M16, AR-15 Condition: New Weight: 0.82 lb Bolt Material: 9310 Steel Carrier Material: 8620 Steel Country of Origin: USA Features of RISE Armament Rifle Bolt Carrier Group BCG, 2AL-BCG-RABCG: Individually MPI tested Bolt: 9310 MPI tested Carrier: 8620 tool steel heat treated and case hardened Gas key: tool steel - grade 8 hardened fasteners and staked properly Cam pin: 4140 steel Extractor: tool steel - shot peened Package Contents: RISE Armament Advanced Bolt Carrier Group, 2AL-BCG-RABCG This product is compatible with the following gun models: AR-15, M16