Prospex Marinemaster 1968 Heritage Diver’s Watch. Seiko Prospex challenges every limit with timepieces created to exceed expectations, engineered with superior style and innovative technology for the sea, sky or land. Driven by rich legacy that has set the standard for dive watch specifications and a heritage of iconic design, Prospex continues to keep going forward with precision timekeeping, crafted for the modern world. An updated homage to Seiko’s landmark 1968 diver’s watch, this extraordinary timepiece is part of the high-intensity Marinemaster collection, complete with a specially engineered, highly accurate mechanical movement and rugged features designed for intrepid divers. Framed by uni-directional rotating bezel with super-hard coating and deep knurling for the ultimate in durability and ease of use, the black dial includes LumiBrite coating on the hands, markers and 12 o’clock bezel marker for superior visibility in low-light conditions and is topped with a dual-curved sapphire crystal with anti-reflective coating on the inner surface. Created with an upgraded 300 meter water resistance, this exceptional timepiece is powered by Seiko’s hand-assembled 35-jewel 8L45 movement that beats at a frequency of 28,800 vibrations per hour with a power reserve of approximately 72 hours, 3 full days and offers enhanced accuracy for the ultimate in precision timekeeping. Crafted of stainless steel with super-hard coating, this rugged high-performance watch also includes a date calendar, secure screwdown caseback, and a tri-fold push button release clasp with secure lock and slide adjuster, allowing for precise size adjustments on the wrist.