La Crosse Technology WT-3161BK 16-Inch Stainless Steel Atomic Clock Brushed aluminum frame Black dial Indoor use only Automatic set time Daylight saving time reset Brushed Aluminum metal frame 16&#034; Diameter 2&#034; Depth Atomic Time with Manual Setting Automatically Sets to Exact Time Accurate to the Second Automatically Updates for Daylight savings time (ON/OFF option) 4 USA time zone settings (ET, CT, MT, PT) Simple Operation: Insert 1 AA Alkaline battery Power requirements: 1 AA alkaline battery (not included) or ADD 2 additional AA to extend battery life (up to 3 years/36 months)