The Crimson Trace model LG-305 lasergrip fits S&W J-frame (small frame) revolvers, round butt, including: Airlight, Airweight, Bodyguard, Chiefs Special, Centennial, Ladysmith models 36, 37, 38, 49, 60, 63, 317, 331, 332, 337, 340, 342, 360, 442, 637, 638, 640, 642, 649, 651 and 940.