The Henzi Pfaff 431 watch movement, introduced in 1962, features a micro rotor and double jewel bearing. It incorporates a double excenter regulator for curb pins and stud carrier, along with a self-winding gear that switches direction through a pinion floating between two large jewels. The movement's indirectly driven minute and second hands enable a low profile design. Minor modifications to the base plate and simplified date driver have been implemented since 1966/67. The movement offers automatic winding, sweep second functionality, and a date feature that can be set by changing 23-24 hours (and since ca. 1966/67, changing 22-24 hours). This movement has been in use since 1962.