Greubel Forsey Double Tourbillon 30°

Double Tourbillon 30° is the collection with which the story of Greubel Forsey begins. The independent Swiss manufacture was founded by Robert Greubel and Stephen Forsey, and the brand's first invention was the double tourbillon inclined at 30 degrees, presented in 2004. The founders' aim was practical: to prove that a tourbillon in a wristwatch genuinely improves timekeeping.

The design is in the name: two tourbillons are nested one inside the other. The inner carriage is inclined at 30 degrees and makes one rotation in 60 seconds. The outer one turns more slowly, completing one rotation in four minutes. The combination of inclination and different rotation speeds averages out rate errors caused by gravity in all the usual positions of a watch on the wrist.

Within the collection, watches are chosen mainly by dial. The Technique version has an open dial, with the mechanism visible from the front. The closed versions are more restrained: a multi-level dial and a separate aperture in which the carriages rotate. A distinct version is the Asymétrique, with a sapphire side window in the case.

One example is the Double Tourbillon 30° Asymétrique in platinum, 43.5 mm: a men's watch with a platinum case and sapphire crystal, a multi-level dial in grey and silver tones and a black leather strap with a platinum buckle. The brand's other collections include Convexe and GMT Sport.