Hamilton Watch Jazzmaster Skeleton Mens H42535541. Let precision take centre stage with the 40mm Jazzmaster Skeleton and its blue cut-out dial, revealing the subtle beauty of this timepiece's inner mechanics. Bringing the H-10-S automatic movement into the spotlight, with an 80 hour power reserve and Nivachron™ balance spring, the Jazzmaster Skeleton is fitted with a sophisticated brown leather strap, showcasing Hamilton's ever-evolving craftsmanship and attention to detail.