This is an original U. Army Air Corps sextant, model F-125, manufactured by Agfa Ansco in the 1940s. It comes with its original instructions and a repair tag dated 12/6/45.
The sextant was used during World War II (1939-45) and is a rare example of field gear from that era. The item is in good working order and would make a valuable addition to any collection of militaria.