Atomic Time with Manual Setting Automatically Sets to Exact Time Automatically Updates for Daylight Saving Time (On/Off Option) 4 USA Time Zone Settings Simple Operation: Insert 1 AA Alkaline Battery Atomic time with manual setting, Automatically sets to exact time, Accurate to the second Automatically updates for daylight saving time (on/off option), 4 time zone settings, Simple operation: insert One "AA" alkaline battery Power requirements: Clock: One "AA" Alkaline Battery (not included) Specifications: After signal is received, press Time Zone button to set, Four Time Zone Settings, Daylight Saving Time Option On/Off, Manual Set Button