This lovely pinwheel calculator is a Felix M, a piece made in the Soviet Union in the 1950s. It is a solid, sturdy and fully reliable machine, an amazing example of the quality and durable designs made in the USSR. The calculator has a grey-enameled cast-iron metal case with hammered finish and white-painted symbols and numbers. The chromed-metal mobile parts are original and remain in great condition, with no traces of rust and in good working order. The calculator can perform the four basic arithmetic operations and is as reliable as when it was originally made. At the front side of the piece we can see the calculators name and model, FELIX M, written in Cyrillic lettering. The first pinwheel calculator was designed by W.T. Odhner in Saint Petersburg in 1886. After the Revolution of 1917, the USSR government nationalized the invention. The Soviets kept on manufacturing Odhner aritmomethers (calculators) under the Iron Felix name after a famous and dark character: Felix Dzerzhinsky. Dzerzhinsky founded the Soviet calculator factory in Moscow in 1924, and was also the founder of the famous Cheka (Bolshevik secret police). He was sadly notorious for his hardness and was awarded the nickname Iron Felix, just like the calculator, among his own colleagues. This fine calculator moves away from the dark story of the person it owes its name: it is a simple, efficient, resistant and attractive machine. At the calculators back we find a series of engraved Cyrillic letters and numbers, among which we can see the possible serial number: 415701. The metalized grey enamel that covers the iron case is well preserved and only show slights signs of wear and few scratches that provide the calculator with charm and personality. Showing off the beauty and quality of Soviet industrial design from the first half of the 20th century, this Felix M calculator is a really historic and interesting item.