This is a neat item, a WW2 MK 12-1 Torpedo Gyroscope with the Bakelite shipping holder. This is serial number 91001 and appears to be excellent unused condition. The MK 12 torpedo was a destroyer-launched anti-surface ship torpedo used by the U.S. Navy in WW 2. The gyroscope provided directional stability for the torpedo on its way to its target during WW 2. These gyroscopes were a most impressive precision instrument and were designed to be destroyed with the torpedo.