KAK Industry K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier Group 9310 Steel NP3 Silver. The K-SPEC is a truly plug and play BCG that will accommodate whatever configuration your mission requires. Specifications for KAK Industry AR-15 K-SPEC Enhanced Bolt Carrier Group: Manufacturer: KAK Industry Caliber: .300 AAC Blackout 5.56x45mm NATO Gun Make: AR Platform Gun Model: AR-15 Gun Type: Rifle Hand: Right Condition: New Extractor Material: 4140 Steel Gas Key Material: 4130 Steel Cam Pin Material: 4140 Steel Carrier Material: 8620 Steel Weight: 11.5 oz Features of KAK Industry K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier Group Dual Ejectors Angled Carrier Rail Cuts Downward Gas Ports Full Auto Profile Package Contents: KAK Industry K-SPEC Enhanced AR-15 5.56 NATO/.300 Blackout Bolt Carrier Group What firearm models does the manufacturer say KAK Industry AR-15 K-SPEC Enhanced Bolt Carrier Group is compatible with? The manufacturer suggests that KAK Industry AR-15 K-SPEC Enhanced Bolt Carrier Group is compatible with AR-15KAK Industry 425-0506-003: K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier Group 9310 Steel NP3 Silver