Working Bézard wrist compass made for the German Bundes Wehr (army) and specially engraved BW. It carries the NATO number from 1971 on the box which reads 6605-12-145-8573. The white straps could be an indication that it was to be used for polar missions. This one is New Old Stock, never used, but the luminous fill from the hands has fell off and is now loose in the fluid. Interesting piece of Nato militaria. The case is plastic, strap real leather and hand are blue steel. Quality product where the Bézard company is well known for. It measures ca. 5,5 cm or 2 1/4 inches in diameter. See attached a short YouTube video on how to works a vintage wrist compass.