This is a relatively late model of the calculating machine invented by the Swede W. T. Odhner in the 1870s and manufactured in Sweden from after World War I. The pinwheel lever-set non-printing machine has a metal frame painted gray with ten 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, for there is no separate set of windows to show these digits.
The carriage is at the front of the machine, with eight windows for the revolution counter on the left. The ten windows of the result register are right of the revolution register. Cranks at opposite ends of the carriage zero the registers on it. Two buttons move the carriage a single place to the right or left. A crank with a wooden knob on the right side of the machine rotates clockwise for addition and multiplication and counterclockwise for subtraction and division. Sliding decimal markers are above the pinwheels, the revolution counting register, and the result register. The machine has a plastic cover.
A mark on the top of the machine reads: Original-Odhner. A paper label glued to the back reads: SKRIVEMASKINE-EXPERTEN (/) KOBMAGERGADE 2 (/) PA. 5291 KOBEBHAVN K. The serial number, stamped on the bottom, reads: 229-2484 (/) MADE IN SWEDEN. A plate under the zeroing mechanism on the right side reads: 5275-00. The inside of the cover has the mark: U. S. Naugahyde (/) 66.
According to the donor, he purchased the machine on a trip to Europe in about 1960 (the instruction manual indicates that the instructions were issued in August of 1967)..