Prospex Diver. Designed for those who treat life as the ultimate adventure, the Seiko Prospex line follows every challenge with technological excellence and style. A contemporary reinterpretation of Seiko's 1965 Diver's watch, this classically rugged design features a stainless steel case with super hard coating, and durable silicone strap. A one way rotating elapsed timing bezel frames a blue dial with date calendar and LumiBrite hands and markers, under a sapphire crystal with anti-reflective coating on the inner surface. The 23-jewel automatic movement beats at a frequency of 21,600 vibrations per hour, with a power reserve of approximately 50 hours, and can be wound manually or automatically. With secure screwdown crown and caseback, this high-intensity timepiece follows ISO standards for scuba diving. 200m Water Resistant.