Prospex PADI Special Edition Special edition celebrating the partnership between Seiko Prospex and PADI, the world's leading scuba diver training organization Patterned and gradated blue dial reflecting the surface of the ocean as seen from under water as the sunlight reaches through the waves on the surface Automatic with manual winding capability 21,600 vibrations per hour Power reserve: approximately 41 hours 23 jewels Blue ceramic uni-directional rotating elapsed timing bezel with vivid blue accents Magnified date calendar LumiBrite hands and markers Sapphire crystal with anti-reflective coating on the inner surface Screwdown crown and caseback Case diameter: 43.8mm Stainless steel case Blue silicone strap Water-resistant to 200 meters (660 feet), Diver's Watch. Follows ISO standards and is suitable for scuba diving Caliber 4R35