The Omega Speedmaster Moonwatch Professional 42mm Sapphire (Reference 310.30.42.50.01.002) is the modern "Sapphire Sandwich" iteration of the iconic Moonwatch. It features a scratch-resistant sapphire crystal on both the front and the caseback, allowing for a clear view of the manual-winding movement.

• Movement: Calibre 3861, a manual-winding Co-Axial Master Chronometer.

• Case Size: 42mm stainless steel with an asymmetrical design.

• Thickness: Approximately 13.18mm to 13.2mm, which is thinner than previous generations.

• Power Reserve: 50 hours.

• Magnetic Resistance: Anti-magnetic to 15,000 gauss (METAS certified).

• Water Resistance: 50 meters (5 bar).

• Bracelet: Polished and brushed five-arched-links-per-row with a new tapered design and a foldover clasp featuring a comfort setting. 

• Applied Logo: Unlike the Hesalite version which has a printed logo, this model features an applied white metal Omega logo on the dial.

• Exhibition Caseback: A transparent sapphire crystal back allows you to view the rhodium-plated finish of the Calibre 3861.

• Step Dial: A black "step" dial inspired by the 4th generation Speedmaster (ST 105.012).

• Dot Over 90 (DON): The anodized aluminum bezel features the historically significant "dot over 90" on the tachymeter scale.