This atomic analog wall clock displays highly visible 1 1/2 in. time numbers that are easily seen across the room. It is radio-controlled so time sets automatically and is always correct even with DST (Daylight Saving Time). The clock movement has a very specialized AM radio receiver that is tuned to receive a 60KHz WWVB time signal broadcast from the U.S. Government's atomic clock in Boulder, Colorado, and Fort Collins. The signal is an AM radio signal? adjusts itself to the U.S. atomic clock's time signal depending on its location. 11 1/2 in. diameter across. Silver trim. White face with black numbers. Uses 1 ''AA'' battery (not included). 1 inch deep.