https://techcrunch.com/2018/09/25/the-horological-machine-9-puts-a-rocket-on-your-wrist/

If you’ve been keeping up with watchmaker MB&F you’ll be familiar with their Horological Machine series, watches that are similar in construction but wildly differ when it comes to design. This watch, the HM9, is called the Flow and hearkens back to roadsters, jets, and 1950s space ships.

The watch, limited to a run of 33 pieces, shows the time on a small forward-facing face in one of the cones. The other two cones contain dual balance wheels. The balance wheel is what causes the watch to tick and controls the energy released by the main spring. Interestingly, MB&F added two to this watch in an effort to ensure accuracy. “The twin balance wheels of the HM9 engine feed two sets of chronometric data to a central differential for an averaged reading,” they wrote. “The balances are individually impulsed and spatially separated to ensure that they beat at their own independent cadences of 2.5Hz (18,000bph) each. This is important to ensure a meaningful average, just as how a statistically robust mathematical average should be derived from discrete points of information.”