USB Powered & Built-in Buffer Battery: This bedside clock includes a USB charging cable so you can conveniently power it. The time display supports 12-hour and 24-hour format. NOTE: When the alarm clock is battery operated, the alarm clock will light up for 5 seconds, then turn off, and turn on again when you press any button on the alarm clock. Save energy and sleep better at night. Easy to Use & Ideal Gift: The watch has been designed with absolute simplicity in mind, and you will have no trouble using it. Exquisite digital clock with accurate time for heavy sleepers, children, teenagers, students, and the elderly. The economical size makes it ideal for your needs as a travel alarm clock, desk clock, or bedside clock. It is a great gift idea for birthday, graduation, housewarming and New Year, etc. Sleek and Simple Design: The modern LED alarm clock has a mirror display and is aesthetically appealing with its sleek design, but can also be used as a mirror if needed.