EVO-9(TM)/TI-RANT 9(TM) PISTON - RIGHT HAND THREADSa A single Evolution 9 or Ti-RANT 9 silencer can be used on a variety of host firearms w/different barrel threads by quickly & easily swapping out the threaded A.S.A.P. piston in the rear of the silencer a All Evolution/Ti-Rant Series Pistons feature heat treated stainless steel a matte bead blasted finish & engraving to identify the thread diameter pitch and direction of rotation for installationCal.: 9mmThread: 1/2x32