Smith and Wesson Model Numbers this Patented Product is designed for: 36, 43, 60, 63, 317, 340, 351, 360, 442, 632, 637, 638, 640, 642, 649. Preferred by gun enthusiasts, law enforcement, and military professionals for concealed carry. This device provides an additional layer of protection without sacrificing speed. Simply put in place behind the trigger, and push outward with your finger to release. The Micro Trigger Stop by Garrison Grip is made of durable rubber to withstand years of use and comes with a Lifetime warranty.