LED Self-set Digital Clock automatically adjusts for Daylight Saving Time so the display is correct from the moment the clock is plugged in, even in buildings that can't receive radio-controlled atomic signals. Easy-to-read, energy-efficient LED screen features bright red, 3.93" high digits for enhanced contrast. LED display also includes calendar, indoor temperature and 12\/24 hour. Mount to your wall or place on a flat surface. TAA-compliant clock is equipped with a 5.6' power cord and battery backup capabilities. It requires two AA alkaline batteries (not included).