Fusion Pro-Series, Firing pin stop plate for 9mm/38 super/ 40 S&W and 10mm slides. Full profile standard profile with radius bottom, Some say these help with recoil and felt control of the pistol shot to shot. All machined from steel Bar stock, heat treated in Black finish. These are Top Quality Professional Series Parts; Made from the best materials and processes available in today’s market. NO-MIM.