The Certina 17-12 watch movement features a pin-lever escapement. It underwent minor modifications during its manufacturing period, with a notable increase in the number of holes. Its calendar function is implemented as a module on the M24 base. The movement offers manual winding capabilities and includes functions such as a sweep second hand, day indication, and a date function set by adjusting the time between 18:50 and 24:00. The M27 movement was primarily utilized around the year 1973.