Laco. An oversized German military manual wind observation watch Circa 1940Laco. An oversized German military manual wind observation watchDate: Circa 1940Movement: 22-jewel manual wind, No.15233Dial: Black, outer 60 second divisions and Arabic five second markers, inner 12 hour chapter, blued steel sword hands with luminous inserts, white centre secondsCase: Polished round, snap on back, fixed bars, band engraved FL23883, No.H15233Signed: Case & dialSize: 55mmIn the 1940's, the German Air Force or Luftwaffe, commissioned watches for their pilots from IWC, Laco, Stowa, Wempe, and A. Lange & Sohne.Produced to the Luftwaffe's specifications, the watches all have a mechanical movement with centre seconds, cases measuring 55mm to accommodate the large movements (which were typically used in pocket watches) and have an oversized crown. The watches would all be fitted on an extra-long leather strap so they could be worn over a flight jacket. The crown could be operated with gloves on pulling it out stops the central seconds. The movement would be surrounded by an iron core, making the watch anti-magnetic.These watches became known as the B-Uhr style, abbreviated for Beobachtungs-uhren, or "Observation" watch. The B-Uhr had two dial variations - Type A dials, such as the present, featured a standard outer minute track and large triangle at 12 o'clock, while the later Type B dials had an inner hour track and outer minute track.The watch cases were engraved on the left side "FL23883" to identify the watch was for navigation. On the inside of the case back, it contained further identifying numbers and information: type (Bauart), production number (Gerät-Nr.), movement (Werk-Bez.), order number (Anforderz), and manufacturer (Hersteller).