Developed during WWII, the M3 was named a "sniper scope" in official nomenclature to obscure its true function as an early infra-red night scope, capable of spotting targets at over 100 yards and detecting other IR-sources up to a mile away. Mounted on an M1 semi-automatic carbine, the scope could be used by night sentries to detect incoming sneak attacks, and direct outbound machine gun and rifle fire with tracer rounds. The scope measures 16 inches long with a Army Corps of Engineers/American Optical Company markings on a sticker on the right side of the base. In a green painted hardwood case with white stenciled "U.S./SNIPERSCOPE/INFRARED/SET NO.1, 20000 VOLTS" on top of the lid, another Army Corps of Engineers/American Optical tag on the inside, Corps of Engineers U.S. Army power pack, rubberized canvas pouch for power pack, attaching wires, and tools. Emitter absent.

Very fine. 90% original black phosphate finish remains on the scope tube with scuffs and dings, visible corrosion on the wires, and handling marks overall. Power pack is fine with scuffs and dings. The scope is untested. Case is also very fine with scuffs and scratches on the exterior.