The Hanhart 126 watch movement, produced between 1949 and today, incorporates a Breguet hairspring and features a stem mechanism without a setting-lever spring. It is considered as one of the first Gruen watch calibers entirely manufactured in the United States. Some variations of this movement may be signed as Gruen:335, with the location specified as Cincinnati and/or U.S.A. rather than Switzerland. This movement operates as a manual wind movement and includes a sub-second function.