The Unitas 155 watch movement is a Chronometro Gondolo open face calibre with a bimetallic screw balance and Breguet hairspring. It features a moustache lever and a cam disc regulator. The movement includes a pink-gold train and wolf teeth winding gear. It also incorporates a flying barrel with Geneva stopwork. The movement allows for stem winding and setting, as well as indicating sub seconds. It was used during the period of approximately 1912.