Revue Thommen was founded in 1853 by Gedeon Thommen and has developed into one of the leading Swiss watch companies with products in the aviation industry. This timepiece features stainless steel case and bracelet, divers scale and a black dial. Case: Brushed and polished stainless steel Caseback: Stainless steel, screw-down Bezel: Polished stainless steel, with a black top ring, unidirectional rotating Dial: Black Hands: Silvertone, luminescent Markers: Silvertone luminescent indices Calendar: Magnified date display window at the 3 o'clock position Bracelet: Brushed and polished stainless steel Clasp: Deployment with safety Crystal: Sapphire Crown: Screw-down Movement: Swiss automatic Water resistance: 30 ATM/300 meters/1000 feet Case measurements: 45 mm in diameter x 12 mm thick Bracelet measurements: 20 mm wide x 8 inches long Box measurements: "[inches wide x inches long x inches high]" Model: 17030.2137 All measurements are approximate and may vary slightly from the listed dimensions. Automatic movement winds with the movement of your arm. It is recommended that you wind the watch every two weeks. A screw-down crown (knob) creates a water-resistant seal. To unscrew the crown, turn counter-clockwise and pull/push into position to set time, date, and other functions. To close the crown, press it against the case and turn clockwise.