Willgodt T. Odhner invented the pinwheel calculating machines in 1878. This machine was made in Goteborg (in English Gothenburg), Sweden with serial No. 7-136833. These types of calculating machines were made continually during the period 1935-1950. The calculator consists of a result register with 13 positions, a proof register with 8 positions and a setting board with 10 positions. The clearing of all registers is performed by cranks. Steel buttons were made for moving the carriage, the panels are made of brass with black color.