310.30.42.50.01.004Ref

Debuting in 2026, the Speedmaster Moonwatch Professional 310.30.42.50.01.004 is a sapphire-crystal variant of the modern Moonwatch, retaining the fourth-generation Apollo-era design with a 42 mm stainless steel case (47.5 mm lug-to-lug, 13.54 mm thick), sapphire front (with inner anti-reflective treatment) and caseback, 50 m water resistance, and a five-arched-link steel bracelet with comfort-adjustment clasp. Its inverted black-and-white double-plate step dial has a black lacquered upper plate and white lacquered subdials framed in rhodium for small seconds, 30-minute and 12-hour chronograph counters, plus a white minute track on the main dial and black transfers on subdials, with rhodium-plated applied markers, logo, and Moonwatch hands filled with white Super-LumiNova, all beneath a black ceramic bezel with white enamel tachymeter including the dot-over-90. The manual-winding, METAS-certified Calibre 3861 operates at 3 Hz with ~50-hour reserve and 15,000 gauss magnetic resistance, visible through the sapphire caseback.