The EVO-9/TI-RANT 9 Piston is an ASAP piston and features heat-treated stainless steel construction. They have a bead-blasted matte finish and are engraved to identify the thread diameter, pitch, and direction of rotation for installation. They come in either left- or right-handed threads. 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 ASAP piston in the rear of the silencer. ASAP pistons are manufactured to match the barrel threads of all popular factory threaded pistol barrels and many aftermarket barrels.