The Tissot 27B-2 watch movement, produced around 1928, is part of the hunter calibre series. It offers options such as a bimetallic screw balance and a Breguet hairspring. The movement is available in various heights, namely 4.1mm, 4.75mm, and 5.0mm, with different bridge shapes found in other versions. While these calibres have limited documentation, this particular line is labeled with the 99 designation, further clarified by its construction height and generation number. It features stem wind and set functionality, as well as a sub-second display.