IWI US, Inc Rimfire, Suppressor, 22 LR, 1/2X28 Direct Thread, Black IWS22 The IWI 22 silencer is a cutting-edge, lightweight, reduced back-pressure solution for .22LR, .22WMR, 17HMR, and 5.7x28. Made with grade 9 titanium internals and a 7075 aluminum body for lightness and durability, it withstands the precise and demanding needs of rimfire and PDW caliber semi-autos, lever guns, and bolt actions of any kind.