A sextant is an instrument used to measure the angle between any two visible objects. Its primary use is to determine the angle between a celestial object and the horizon which is known as the altitude. This WWII Fairchild USAAF A-10A Sextant was issued during World War two to personnel from the Army Air Force (AAF). I love intricate instruments like this, even if I don't have a clue how they work. These were for sale, with their wooden box and extra parts, for $195. This will be ...much cheaper. The optics are clear, the dials seem to work, but I don't know that you could use it without its other parts. Thanks for looking