Lange & Söhne observation watch, control watch, WW II, circa 1944, naval requisition number M 17415, from the Lange und Söhne Glashütte movement, No. 204742, movement, case and platinum numbers are the same, silvered dial with arab. numerals and blued lance hands, indication power reserve (up and down) at 9 o'clock, small second at 3 o'clock, gold plated movement cal. 48 with bimetal compensation balance and Breguet hairspring, swan neck fine regulation, the special anchor still used at the beginning, movement runs exactly, plexiglass, diameter 60mm, height 18mm, weight approx. 168,5g, case shows signs of wear, dial 1A