; The 3rd generation Skyhawk redefines atomic timekeeping with radio-controlled accuracy and Eco-Drive technology. Radio signals are received both automatically and on-demand by the fully loaded Skyhawk A-T. Using the most advanced technology in watch making, the Skyhawk never needs a battery. Citizen's Eco-Drive technology harnesses the power of light (natural or artificial) and converts it into energy which is stored in a permanently rechargeable lithium-ion cell. The cell recharges continuously and when fully charged has a power reserve of 240 days. Quick start-up after exposure to light. Atomic timekeeping with radio-controlled accuracy. World time in 43 cities. 2 alarms. 1/100 second chronograph measures up to 24 hours. 99 minute countdown timer. Perpetual calendar. Digital display light. Greenwich mean time display. Rotating slide rule bezel. Power reserve indicator. All stainless steel black plating. Water resistant to 200m. Non-reflective mineral glass crystal. Fold over clasp with hidden double push button. Dimensions: Face Width 45mm Face Height 45mm Face Depth 16mm Band Width 20mm Band Circumference 8.5 inches ; Citizen Watch offers a five-year limited manufacturer's warranty on all their products. For more information, please visit their website and see the Service Information section.