Seiko Prospex Diver SPB051Seiko Prospex Automatic Diver Specifications Contemporary reinterpretation of Seiko's 1965 Diver's watch Manual and automatic winding capabilities 21,600 vibrations per hour Power reserve: approximately 50 hours 23 jewels One way rotating elapsed timing bezel Date calendar Black dial Screwdown crown and caseback LumiBrite hands and markers Sapphire crystal with anti reflective coating on the inner surface Case diameter: 42. 6mm Stainless steel case