Atomic Accuracy: The Atomic clock has a built-in receiver that automatically synchronizes itself with the WWVB radio broadcast by the US Government's National Institute (NIST) in Fort Collins, Colorado. The Atomic Clock will always be accurate to within one second as it receives daily WWVB updates.
Wireless Outdoor Sensor: The Wireless outdoor sensor (included) transmits the outdoor temperature to the Atomic Wall Clock. The sensor can be placed anywhere within 100ft of the receiving unit. The wireless technology means no wire installation is necessary.
Jumbo 3" Tall LCD Time Display - Easy to Read, Easy to Use, Easy to Set up
Displays indoor and outdoor temperature - Displays calendar and day of week
Battery powered: Main unit 3 x AA batteries - Sensor 2 x AA batteries (not included)