This is a highly desired Seiko professional dive watch that is nicknamed the Tuna or Tuna Can.
It features a 7-jewel, Seiko 7C46 movement that is accurate to within at least 15 seconds a month. a Hardlex crystal, and a solid etched, screw-down case back.
Specifications:
Stainless Steel Case Unidirectional Rotating Bezel Dual Curved Hardlex Crystal Polyurethane (Rubber) Strap 7C46 Quartz Caliber Screw Down Crown Accuracy of +/-15 Seconds per Month Water Resistant to 30 Bar / 300m Designed for Saturation Diving Day/Date Display Case Diameter: 46mm Case Thickness: 14.7mm Band Width: 22mm
this Seiko Marinemaster SBBN017 Professional Diver Tuna 300m that can withstand mixed-gas use for diving,