Cased Wehrmacht Slide-Ruler (Rechenschieber). Slide-ruler as used for map and artillery calculations in the field. The slide-ruler is made of wood and plastic, it is nicely maker marked with 'cme' and WaA marked and comes in it's matching marked leather carrying case. 'cme' is indicating production by the company 'Gebr. Wichmann' from Berlin. The two small plastic pins have been damaged, see close up. Rare and hard to find original military piece of measuring equipment!