Kwanwa Cordless LED Clock, Which Use 2 Battery Only and Can Keep The Led Time Display for More Than 1 Year Without Any External Power Supply Only use 2 D size Alkaline Battery which can keep the Led time display on more than 1 year without any external power supply Average working currency is smaller than 1ma. Comes with date and temperature display function and one daily alarm can be set. Battery powerd and cordless Display will become dim automatically during AM12:00~AM5:00.