Prospex Speedtimer 1/100 Second Solar Chronograph Inspired by Seiko's – and the world's – first analog quartz chronograph, which featured a 1/100-second stopwatch Features 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 function Powered by light energy – no battery change required 6-month power reserve once fully charged White dial with four inset black subdials, including a separate time dial LumiBrite hands and markers Curved sapphire crystal with anti-reflective coating on the inner surface Concave top hammer-shaped pushers for easy stopwatch timing Screwdown caseback Case diameter: 42.0mm Stainless steel case and bracelet Tri-fold push button release clasp Water-resistant to 10 bar, 100 meters (330 feet) Caliber 8A50