YHM's .30 caliber sound suppressor, the Resonator(R) R2, can be used on rifle calibers ranging from .17 HMR through 300 RUM. Like the Turbo(R) T2, the Resonator(R) R2 uses a tubeless design which consists of heat treated 17-4 stainless steel and a heat treated 718 Inconel blast baffle which allows the suppressor to be full auto rated and designed for rigorous use. Includes YHM-4302 Q.D. Mount of your choice. Sound Pressure levels are as follows: 20" Remington 700 shooting .308 Winchester 147 grain measured 135Db 16" 6.8mm AR-15 shooting 110 grain measured 132.5Db 14.5" 5.56mm AR-15 shooting 55 grain measured 132Db The Resonator(R) ships with the Phantom(R) Q.D. Adapter, 2 suppressor wrenches, and a YHM-4302 mount. It will fit all YHM-4302, YHM-3302 and YHM-3102/YHM-5M2 mounts.