Prospex Prospex Collection Japanese Automatic Chronographs Watch With A Stainless Stell Bracelet Strap, 42.5mm Case & Blue Coloured Dial With Date Window. DESCRIPTION The Speedtimer Prospex watch collection represents Seiko’s professional timekeeping heritage. This particular design is inspired by two 1969 models – the world’s first automatic chronographs with a column wheel and vertical clutch. – but features new innovations, including high contrast dial and subdial colours for legibility and the 8R calibre. Becoming official timekeeper for Tokyo’s high profile international sports event in 1964 was a turning point in Seiko’s history. Making precisely accurate professional timing instruments, with no prior experience, resulted in the Seiko Watch Corporation design code of visibility, legibility and functionality. Prospex is a combination of the words ‘Professional’ and ‘Specifications.’ These timepieces are designed to be practical, reliable and durable within extreme or everyday environments, for experts, sports lovers and adventure seekers alike. SPECIFICATION Accuracy: -15/+25 seconds per day Calibre: 8R46 Movement Type: Automatic & Manual Winding Power Reserve: 45 Hours Case: Stainless steel (Super Hard Coating) Case Thickness: 15.09mm Case Length: 50.0mm Lug Width: 20.0mm LumiBrite: Lumibrite on hands and indexes Clasp: Three-fold clasp with push button release Crystal Coating: Anti-reflective coating on inner surface Crystal Type: Dual-curved sapphire crystal