Special Edition : White Color : Waterproof clock. * Sets itself by automatically using the broadcast from an atomic clock in Boulder, Colorado. * Accurate to 1 second every 60 million years. * Signal is broadcast all over North America by the National Institute of Standards and Technology. * Includes day of the week and alarm . *** The Proper way to use the suction cup *** 1) Unscrew the back from the Clock 2) remove plastic Back 3) press silicone suction cup againts the wall (remember without plastic back) 4) screw clock into Suction Cup Mount