1 / 1 Historiques Ultra-fine 1955 Vacheron Constantin 1955 Vacheron Constantin: Historiques Ultra-fine 1955/1955 This mechanical hand-wound watch, the thinnest in the world at just 4.10 mm thick, celebrates the 55th anniversary of the legendary ultra-thin Calibre 1003, rebuilt for the occasion in 18-carat gold and bearing the prestigious Hallmark of Geneva.