Seiko Prospex Solar Chronograph SSC423 SSC423P1 SSC423P Men's Watch The Seiko Prospex series now runs on the power of light alone, thus increasing its reliability. Designed to be used on land, under the sea or in the sky, the Seiko Prospex Solar Chronograph stands confidently against the challenges of the harsh outdoors, delivering precision and extreme durability even under the most adverse of conditions. With its trigonometric slide rule, no calculation related to distance, fuel consumption or speed is complex anymore. Features: Stainless Steel Case Black Leather Strap Solar Powered Caliber: V176 Mineral Crystal Black Dial Luminous Hands And Markers Chronograph Function Power Reserve Inner Rotary Slide Rule Bezel Date Display Pull Out Crown Buckle Clasp 100M Water Resistance Approximate Case Diameter: 43mm Approximate Case Thickness: 13.5mm