Osprey .38 Special Arbor Sleeve for the .30 Carbine Laser Bore Sight Cartridge Fits: .38 Special, .357 Magnum, Please note, this arbor will not work with handguns chambered in the .357 SiG round. Minimum Range in Yards for Sighting in is 15 Yards. Maximum Range in Yards for Sighting in is 100 Yards Wave Length of the Prime Cartridge is 645nm Operation is by the On/Off End Cap