KAK Industry K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier 9310 Steel Chrome Silver. Ejector holes are centered on the lugs to avoid any reduction in strength of the bolt. The dual ejector system increases the ejection reliability and adds consistency to the ejection pattern. Specifications for KAK Industry K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier: Manufacturer: KAK Industry Color: Silver Finish: Chrome Fabric/Material: 9310 Steel Caliber: 5.56mm .300 AAC Blackout Gun Make: AR Platform Gun Model: AR-15 Gun Type: Rifle Features of KAK Industry K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier Complete Assembled Bolt Only Duel Ejector 9310 Steel Machine Gun Chrome Finish Backwards Compatible with All Standard Mil-Spec BCG Components Can be used in any AR-15 Style Direct Impingement System Package Contents: KAK Industry K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier What firearm models does the manufacturer say KAK Industry K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier is compatible with? The manufacturer suggests that KAK Industry K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier is compatible with AR-15KAK Industry 303-0505-002: K-SPEC Enhanced AR-15 5.56mm/.300 AAC Blackout Bolt Carrier 9310 Steel Chrome Silver