The Marvin 525B watch movement, similar to the ETA 717 movement but with lower specifications, is equipped with an early Incabloc shock device. The differences between the Marvin 525B and the Zentra 295 movements are unclear. There are various samples of the Marvin 525B movement that exhibit both bridge layouts shown in the archived records. The Marvin 525B movement is a manual wind movement with sub-second functionality, and it was primarily used around the year 1935.