H. Moser & Cie Caliber HMC 804

The H. Moser & Cie caliber HMC 804 is an in-house automatic tourbillon movement.

This calibre is found in the Streamliner Tourbillon Vantablack which was launched on August 24, 2022.

In H. Moser’s own words:

“The HMC 804 is an automatic tourbillon movement which counteracts the effects of gravity in two ways: the one-minute flying tourbillon, and the patented double hairspring where two identical hairsprings compensate for any positional errors.” –source

And this:

“Conceived to counteract the effects of gravity on the watch’s timekeeping precision, the tourbillon is a device in which the regulating organ and escapement are placed, which constantly rotates around a central axis to eliminate any positional errors.” -same source

Additional Resources:

• H. Moser Streamliner Tourbillon Vantablack official page
• Official video announcement