This atomic clock automatically resets itself to the correct time! digital clock displays the time, date, time zone and temperature in large, easy-to-read numbers. The alarm has a snooze function, and the background lights up to read it at night. Req. 2 "AAA" batteries (sold separately). Plastic. 5 1/4"L x 2 1/4"W x 3 3/4"H.