By Cox & Stevens Aircraft Corporation. Load adjuster for the Douglas C-47 'Skytrain' (British Dakota). Looks similar to a conventional slide rule but was used to ensure the correct weight distribution throughout the airframe depending on the amount troops on board, whether a jeep, anti-tank gun or howitzer is included etc. In very good condition with sliding perspex 'curser' and leather hardcase. The C-47 was used extensively during WW2. The ID card within the case is numbered 42-24254. This aircraft was manufactured by Douglas at Long Beach under contract No. 10116. Stock code M22825.