The Seiko W601-4000 watch movement, used during the period from 1968 to 1972, featured various noteworthy characteristics. These include a Triovis micrometer regulator, an electromechanically controlled balance motor, a hack mechanism that stops the balance in a specific position for reliable starting, and a sweep second function. Notably, the watch is electronic, equipped with shock protection, a stop seconds function, and a sweep seconds hand. Furthermore, early samples of the movement had a setting-lever screw, while the later ones had a slide to release the stem. There is also a feature where the battery clip can be secured with a screw on the bridge if the battery is held by the back. However, further elaboration on these functions is not provided.