Sinn Spezialuhren GmbH & Co. KG was founded in 1956 by Helmut Sinn. It mainly pilot watches and chronographs were manufactured, which could be offered by the direct sales at unrivaled low prices. In September 1994, Helmut Sinn sold his company to the former IWC employee and engineer Lothar Schmidt. Helmut Sinn was active in the old age as a watch maker with the brands Guinand, Chronosport and Jubilar.