Originally manufactured by Winchester as a Model 37 single barrel shotgun, this shoulder arm was refitted by the Naval Company of Doylestown, Pennsylvania as a dedicated line thrower powered by 45-70 caliber blanks. A large aluminum line canister is attached to the forearm and barrel, which have both been shortened, the former sanded down to fit the cylinder bracket and the latter stamped with Naval's markings. Smooth pistol grip stock, with a brass instruction plate and slip-on Pachmayr recoil pad. With a hardwood case, 10 brass projectiles, 3 reels of line, 3 spindles for re-winding the line, 30 blank cartridges (20 in box, 10 in sealed can), cleaning tools and papers.