Osmior Régulateur à Tourbillon Squelette

The L.Leroy Osmior Régulateur à Tourbillon Squelette (Ref. LL108/1) is a high horology, self-winding regulator tourbillon introduced in 2011 as part of the Osmior collection, produced in a 7-piece limited series (each watch individually numbered 1/7 to 7/7). Its 41 mm round case is crafted in 18-carat pink gold (4N), with a slim 10.5 mm profile and 50 m water resistance. The watch is fitted with sapphire crystals featuring multi-layer anti-reflective treatment, plus an open/engraved sapphire caseback that reveals the movement. It is paired with a black hand-sewn alligator leather strap and a pink gold pin buckle.

Powered by a self-winding mechanical skeleton movement (manufactured in the Vallée de Joux for L.Leroy), operating at 28,800 vph (4 Hz) with a 52-hour power reserve and 23 jewels. The calibre includes an openworked 22k gold central oscillating weight with unidirectional winding. The movement is hand skeletonised and hand finished, with hand beveling and decorative finishing throughout. Its regulator display separates the indications for improved legibility and chronometric tradition, with functions for hours, minutes, small seconds, and flying tourbillon. The flying tourbillon features a variable-inertia balance, double balance spring, and diamond lever escapement, designed to improve precision, stability and reduce wear. The model is described as chronometer grade, with references to COSC certification and official observatory chronometer credentials (including the Besançon “Tête de Vipère” mark), reinforcing its emphasis on precision as well as artisanal finishing.