The AR-15 9mm Complete Bolt Assembly is designed for semi-automatic operation and features a durable black finish for reliable performance in 9mm AR-15 builds.AR-15 9mm Complete Bolt AssemblyCompatible with Glock and Colt magazinesBlack anodized finish for durabilitySemi-automatic operation onlyComplete bolt assembly ready for installationEssential component for building or upgrading 9mm AR-15 platforms offering versatility with both Glock and Colt magazine systems for enhanced reliability and performance.