Smith & Wesson Rear Night Sight S&W 4006TSW, 4046TSW, 5906TSW, CS9C, CS9S, 3904, 3906, 3913, 3914, 3944, 3946, 3953, 3954, 4003, 4004, 5903, 5903SSV, 5904, 5906, 5923, 5924, 5926, 5943, 5943SSV, 594