Prospex Automatic Diver Manual and automatic winding capabilities 21,600 vibrations per hour Power reserve: approximately 41 hours 24 jewels Black ceramic one-way rotating elapsed timing bezel Black dial with 3-D pressed pattern Magnified day/date calendar LumiBrite hands and markers Sapphire crystal with anti-reflective coating on the inner surface Screwdown crown and caseback Case diameter: 45.0mm Stainless steel case and bracelet Water-resistant to 200 meters (660 feet), Diver’s Watch. Follows ISO standards and is suitable for scuba diving. Caliber 4R36