This new Baby Tuna is a part of Seiko's international Prospex releases. The shroud is different here; it is hardened composite material and the movement, a self-winding Seiko 4R36. It has both hack and manual winding features and the hardened mineral on top is a Hardlex crystal. It is still the best for shatter resistance while the Lumibrite lume takes a minute in the sunlight to charge and glow brightly for the next 15 minutes.
Black IP Stainless Steel Case Polyurethane Strap Automatic Movement Caliber 4R36 Hardlex Crystal Black Dial Luminous Hands And Markers One Way Rotating Elapsed Timing Bezel Day And Date Display Screwdown Crown Buckle Clasp 200M Water Resistance
Approximate Case Diameter: 47mm Approximate Case Thickness: 14mm