Luftwaffe 'DR 2' Flight Navigation Computer (Dreieckrechner). The Luftwaffe used two different models of manual flight navigation computers which were basically circular slide rulers to assist in navigation calculations. The flight navigation computer is having a diameter of 15cms and the computer is nicely maker marked by the company of 'C. Plath' from Hamburg and dated January 1941. It comes in its rarely seen original protective cover made of some sort of black coloured 'Ersatz' material. Nice set in good condition!