Revue Thommen was founded in 1853 by Gedeon Thommen and has since developed into one of the leading Swiss watch companies. Early on, only wristwatches and pocket watches were produced and they relied exclusively on their own movements. In the 1920s Revue Thommen also started producing instruments for the aviation industry. This segment was constantly expanded, and today, Revue Thommen's instruments are among the leading products in the aviation industry. Case: Stainless Steel, Round Caseback: Sapphire, Screw-down, Transparent Bezel: Stainless Steel, Silvertone, Fixed Dial: Silver, analog Hands: Silvertone Markers: Indexes Calendar: Date display window at the 3 o'clock position Functions: Hours, Minutes, Seconds, Date, GMT Strap: Stainless Steel, Silvertone Clasp: Push-button Deployant, Stainless Steel Crystal: Sapphire Crown: Stainless Steel, Push-pull Movement: SW330-1/ C125 Automatic GMT Movement, 28‘800 oscillations Water Resistance: 5 atm/50 meters/165 feet Power Reserve: 42 Hours Case measurements: 41 mm in diameter x 12 mm thick Strap measurements: 20 mm wide x 8 in long Country of Origin: Switzerland Model: 21010.2332