Power : 3 X AAA batteries (not included) Color: Black Shell Material: Plastic Size: Approx. 130x72x44mm The clock illuminate automatically for easy night-time viewing screenLarge LCD Display、 easy to read numbers and power saving Timing function、 perpetual calendar and 24 hours / 12 hours transition functionIntelligent white backlight、 built-in sensor to turn on/off the backlight automaticallyCan be placed in the car、 office、 home