HITO Atomic Radio Controlled Multifunction LCD Travel Alarm Clock w/ Backlight, Smartlite, Calendar, Week, Temperature(C/F) (Black) Radio-controlled automatic time and date update with Daylight Saving Time (DST) - Simply insert batteries. Battery operated: three AAA batteries needed (not included). Clock size: 2.6 x4.2 x0.8 inches. Jumbo big digit display; Display of Time (12/24 hr), Alarm Status, Date (mm-dd), Day of the Week & Temperature (C/F) 5-minute repeating SNOOZE feature. Many options to turn OFF alarm. Smartlit Feature: Smartlit sensor enables LCD display to stay illuminated in dark conditions; also automatically turns off the dim light in bright conditions to prolong battery life.