Stern Defense 9mm Complete Bolt Carrier Group, Mag-Phosphate Finish - SD BU9

- Stern Defense 9mm Complete Bolt Carrier Group - Finish: Mag-Phosphate - Material: 8620 AISI steel - Compatible with Mil-Spec and Glock-pattern upper receivers - Works with Colt SMG and Glock magazines - Fully compatible with standard AR-15/M16 charging handles - Comes fully assembled with all sub-components installed, including firing pin, firing pin spring, retaining pin, extractor, and extractor spring - Includes proprietary center and roll pins - Ready for AR-15 platform use