Prospex Speedtimer Solar Chronograph. Design inspired by Seiko's 1969 Speedtimer, one of the world's first automatic chronographs. Powered by light energy - no battery change required. 6-month power reserve once fully charged. Chronograph measures up to 60 minutes of elapsed time in 1/5-second increments with split time measurement function. Silver dial with sunray finish, black subdials, and red accents. Date calendar. 24-hour subdial. LumiBrite hands and markers.Curved sapphire crystal with anti-reflective coating on the inner surface. Dual-tone black and gray tachymeter bezel. Screwdown caseback. Case diameter: 41.4mm. Stainless steel case and bracelet. Tri-fold push button release clasp. Water-resistant to 10 bar, 100 meters (330 feet). Caliber V192