The ASR (Active Spring Retention) Mount is a quick attach / detach system for almost all SilencerCo suppressors. The simple one-hand-on one-hand-off mounting system is compatible with all ASR Muzzle Devices to promote ease of transfer from one silencer to another. Once shouldered the locking ring ensures the silencer won’t rotate or work itself loose under a heavy firing schedule. Compatible with Harvester EVO Harvester 338 Omega 300 and Hybrid 46.