Take to the skies with the Citizen Promaster Sky, styled in stainless steel case with black bezel and blue dial. Featuring radio-controlled atomic clock synchronisation for superior accuracy in 24 worldwide cities, 1 second chronograph measuring up to 60 minutes, alarm, 12/24 hour time, perpetual calendar and a compass ring rotating bezel. Powered by Eco-Drive- the revolutionary light powered movement from Citizen, this watch has the ability to continuously recharge in any light source and can run for a minimum of six months even in the dark without any charge. This revolutionary earth friendly technology eliminates the need to change battery frequently and gives you hassle free timekeeping, never disappointing you when you need it the most. The Eco-Drive movement also comes with built-in Insufficient Charge Warning Function and Overcharge Prevention Function.