The Kaw Valley Precision Muzzle Brake 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 Bore: .500 (ANY Caliber) Specifications for Kaw Valley Precision Muzzle Brake Mount for ASR: Manufacturer: Kaw Valley Precision Color: Black Finish: Black Nitride QPQ Fabric/Material: 17-4 Stainless Steel Length: 2.05 in Weight: 3.6 oz Condition: New Size: Small Package Contents: Kaw Valley Precision Muzzle Brake Mount for ASR