The Fontainemelon 642 watch movement, similar to the ETA 717 movement but with lower specifications, is equipped with an early Incabloc shock device. The differences between the Fontainemelon 642 and the Zentra 295 movements are unclear. There are various samples of the Fontainemelon 642 movement that exhibit both bridge layouts shown in the archived records. The Fontainemelon 642 movement is a manual wind movement with sub-second functionality, and it was primarily used around the year 1935.