Citizen Eco-Drive technology with atomic timekeeping makes this the most accurate watch in the world. This perpetual calendar is radio-controlled in 5 time zones, boasts a 1-second chrono that measures up to 60 minutes, and power reserve. Shown in titanium with black ion plating and blue & luminous accents under non-reflective sapphire crystal. Featuring our Eco-Drive technology – powered by light, any light. Never needs a battery. Caliber number E650.