Original Odhner Model 39

This Swedish lever-set non-printing pinwheel calculating machine has a metal frame painted black, with eight metal pinwheels and a metal base. Numbers are set by rotating the pinwheels forward, using levers that extend from the wheels. Digits inscribed on the frame next to the rotating pinwheels show the number set, as well as a set of windows above the pinwheels that shows these digits.