Tag Heuer Caliber V4

The TAG Heuer caliber V4 is a belt-driven tourbillon movement.

Originally inspired by Formula One engines, TAG first introduced a concept version of the calibre V4 at Baselworld 2004. 10 years later, in 2014, TAG reintroduced the Monaco V4 Tourbillon.

In TAG’s own words:

“The Monaco V4 is the world’s first watch with belt drives, linear mass and ball bearings. Industrialized and entirely hand manufactured in TAG Heuer workshops, this double patented timepiece is the next step forward in the evolution of TAG Heuer’s iconic squared-faced Monaco — the audacious chronograph first seen on Steve McQueen’s wrist in the 1970 race film classic, Le Mans. This breakthrough innovation redefines the accepted conventions of watch engineering and aesthetics.” -TAG Heuer

The belts mentioned in the excerpt above are said to be only .07mm thick! There are four of them, hence the moniker V4.

Additional Resources:

• More on the Tag Heuer V4 at tagheuer.com