Prospex King Sumo Blue 'Gradation' SPB321J1

This watch shape is affectionately named 'Sumo' by Seiko fans because of its size and shape and the 12 o'clock marker - it's a substantially strong looking timepiece. This latest design has been updated with new modern features, including a ceramic bezel and super hard coating on the case and bracelet for durability. A new 3 row bracelet has been specifically made for this model, while the clasp has also been modernised. The dial features a fine pressed pattern dial with gradations of blue. Prospex is a combination of the words 'Professional' and 'Specifications.' Seiko Prospex timepieces are designed to be practical, reliable and durable; to meet the high standards required in extreme environments for sports lovers and adventure seekers alike. Since launching Japan's first diver's watch in 1965, Seiko's innovative watchmaking has changed global dive watch standards.

Movement
Accuracy: -15/+25 seconds per day
Calibre: 6R35
Movement Type: Automatic with Manual Winding
Power Reserve: 70 Hours

Watch Case
Case Material: Stainless steel (Super Hard Coating)
Case Thickness: 13.35mm
Case Diameter: 45.0mm
Case Length:52.57mm
Lug Width: 20.0mm

Exterior
Dial Colour: Blue
LumiBrite: Lumibrite on hands, indexes and bezel
Clasp: Three-fold clasp with secure lock

Other Specifications
Water Resistance: 20 bar
Crystal Type: Sapphire crystal