Universal’s “Compax” was introduced in 1935 as the world’s first chronograph wristwatch with hour and minute registers. Members of armed forces around the world appreciated this new style for its functionality. Models were available in different case materials and forms, as well as a variety of dial layouts using the names ‘Tri-Compax,’ ‘Uni-Compax,’ and Aero-Compax.’ Released in 1941, the “Aero-Compax” was a professional tool watch made for pilots. With different dial configurations, the present example belongs to a rare breed of the model, featuring a bi-colored 24-hour rotational bezel and 24-hour dial. The bezel is used to determine a second time-zone based on distance travelled, while the hands sweep once around the dial every 24 hours. Another unusual feature is the 15-minute register, which moves twice per minute capturing 30 second intervals. Universal Genève used a modified Venus 178 base caliber to accommodate these two unusual complications.

The present example is in outstanding overall condition, most likely never polished, with a well preserved dial. The Aero-Compax is regarded as one of the most important milestone timepieces for Universal Genève, and this is a wonderful example of the rare model.