Laser sights for Smith & Wesson K, L & N Frame revolvers feature a polymer material that provides ideal grip security for large caliber revolvers. The laser activation switch is located in front, making activation "instinctive" when you assume a normal firing grip on the revolver. *Fits both round and square butt S&W Model 10 through 29, 48, 53, 56, 57, 58, 64, 68, 242, 329, 396, 530, 547, 581, 586, 610, 617, 624, 625, 627, 629, 648, 657, 686 and 686. **Does not fit K-Frame Scandium revolvers and models with target hammer.