This is a U.S. Navy Aircraft Telescope Sight — Mark V Mod 1, measuring approximately 10 inches in length. The sight features coated optics, as indicated by the marking, designed for clarity and durability in challenging conditions. These optical sights were typically used on naval aircraft or gunnery systems during mid-20th century service (likely WWII through Korea or early Cold War). The body is black-finished metal, with a rubberized or Bakelite eyepiece that shows characteristic age cracking. The sight is marked:
