The Timex M31 watch movement, utilized from 1968 onwards, is an automatic mechanical movement with a frequency likely set at 18,000 beats per hour. Notably, the train and hand gear are independently driven by the barrel. Additionally, the movement incorporates an offset center wheel and offers functions such as automatic winding, sweep seconds, and a date feature, which can be adjusted by changing the time between 19:20 and 24 hours.