This 2021 design is inspired by Japan’s first diving watch, created by Seiko back in 1965. It comes with calibre 6R35 and its long lasting 70 hour power reserve, accompanied by Seiko's first ever original nylon strap for diver's watches – the 'SEICHU,'' crafted in Japan, designed for flexibility and durability. 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. The Seiko SPB239J1 Prospex watch combines a 40.5mm round shaped super hard coated stainless steel case and comes with two interchangeable NATO straps in khaki and dark brown. It has a black analogue dial with Lumibrite coated hands, indexes and bezel, in addition to a date display, all of which is protected beneath scratch resistant curved sapphire crystal glass with an anti-reflective coating on the inside. Power is generated by the Calibre 6R35 automatic movement with 24 jewels and a 70 hour power reserve. This model also has a water resistance of up to 200 metres and weighs 106 grams.