The Puw 663 watch movement is part of a series of hunter calibres with construction heights of 4.1, 4.75, and 5.0mm. It features different bridge shapes compared to other versions within the series. The calibres in this series, including the Puw 663, have limited documentation in the literature. The distinguishing feature of this movement, as with others in the series, is the extended calibre number which includes the construction height and generation number. The Puw 663 movement functions include stem winding and setting, as well as a sub-second display. It was commonly used around the year 1940.