The Kaw Valley Precision Flash Hider is seamlessly engineered to be fully compatible with ASR (Active Spring Retention) mounting systems. Designed to effortlessly attach and detach from your firearm, our brake ensures quick and hassle-free adjustments to your shooting setup without the need for timing or shims. Compatible with the following SilencerCo ASR mounting systems: Alpha: Harvester 300 and Omega K Series, and Octane Series Bravo: Harvester EVO, Hybrid 46, Harvester 338, Omega 300, and Scythe-Ti Charlie: Saker ASR Series, Chimera 300, Omega 36M, and Hybrid 46M Features: 17-4 Stainless Steel Material Black Nitride QPQ Finish OAL: 2.05 Bore: .500 (ANY Caliber)