Caliber 20

The Caliber 20 is presented by RGM in 2013 as a new proprietary caliber tied to the brand's journey through its first twenty years of activity. Unlike the Caliber 801, designed for a round case of classic taste, the Caliber 20 is developed specifically for a tonneau case, with a movement architecture built to measure for this shape.

The caliber's most distinctive technical feature is its "motor barrel" system, which reverses the traditional roles of barrel and winding spring: a solution once used by higher-end American railroad pocket watches, such as the Illinois Bunn Special or the Hamilton 950, to reduce the risk of mainspring breakage. By reviving this system in an entirely new caliber, RGM presents it as a further direct nod to the great American railroad watchmaking tradition, the same one already celebrated in other lines of the brand.

The dial, in solid silver in the main version, incorporates a seconds counter with a rotating disc and a moon-phase function framed by a ring with Roman numerals; blued-steel hands complete the classic aesthetic. The movement, hand-finished with Côte de Genève, perlage and beveled edges, is visible through a sapphire case back even in the non-skeletonized version; RGM also offers variants with a skeletonized movement or a fully guilloché dial.