Convert your SRD45 suppressor to a 9/16x24 Right Hand thread pitch with the SRD-PISTON-916X24. The piston is made of 17-4 heat treated stainless steel with a matte glass bead finish. The piston will fit a variety of hosts and it is a perfect choice for converting your SRD45 to .40 S&W or 10mm (sub-sonic). Simply swap the conversion piston with the original piston in your silencer to match your barrel thread pattern.