Prospex Speedtimer1964 Chronograph Recreation Introducing an entirely new Prospex watch collection, inspired by Seikos professional timekeeping heritage. This timepiece inspired by the original 1964 chronograph stopwatch. Becoming official timekeeper for Tokyos high profile international sports event in 1964 was a turning point in Seikos 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 wordsProfessionalandSpecifications.These timepieces are designed to be practical, reliable and durable within extreme or everyday environments, for experts, sports lovers and adventure seekers alike. Calibre: 8R46 Movement Type: Automatic & Manual Winding Accuracy: -15/+25 seconds per day Case Material: Stainless steel (Super Hard Coating) Case Diameter: 42. 5mm