The Unitas 453 watch movement, which is a hunter calibre with a set-lever spring positioned between the plates, offers several customizable options including a bimetallic screw balance, Breguet hairspring, and Reed's regulator. Noted differences between the Alpina 292 and 1720 are currently unknown. This movement, introduced in approximately 1920, features functions such as stem wind and set, as well as a sub-second display.