A single Evolution 9 or Ti-RANT 9 silencer can be used on a variety of host firearms with different barrel threads by quickly and easily swapping out the threaded A.S.A.P. piston in the rear of the silencer. All Evolution/Ti-Rant Series Pistons feature heat treated stainless steel construction a matte bead blasted finish and engraving to identify the thread diameter pitch and direction of rotation for installation (Left Hand threads or Right Hand threads). - Caliber: 9mm - Thread: 1/2x28 - Not Compatible With The TiRant45