HTAWI HAA-1004M 10.5 Inch Brushed Steel Analog Atomic Wall Clock High quality construction with a scratch resistant glass face to endure many years of cleanings Atomic clock is accurate to 1 second per million years Atomic clock movement sets automatically to WWVB radio signal Switch selection for all four U.S. mainland time zones Atomic clocks automatically adjust for daylight savings time (may be optionally disabled)