Seiko Prospex SFJ001 Speedtimer ChronographProspex Speedtimer 1 100 Second Solar ChronographInspired by Seiko's and the worlds first analog quartz chronograph, which featured a 1 100 second stopwatchFeatures the new solar chronograph 8A50 movement, with precision stopwatch timing to 1 100 second, measurement up to 60 minutes of elapsed time, and a split time functionPowered by light energy no battery change required6 month power reserve once fully chargedWhite dial with four inset black