Alarm Digital Clock for Kids Bedrooms Auto DST, Alarm, Calender, 12/24 Hour, Backlight, Volume, Colors, USB. Size: 0.9 in*2.2 in*5.5 in. Kids Alarm Clock with 7 Colors Changing Kids digital clock, different options from solid color numbers and numbers that change colors. Also for Heavy Sleepers Adults Teens. 4 Kinds of Adjustable Backlight With attached usb for full functional screen, the backlight is adjustable: from HIGH to OFF. The battery (not included) is mainly used to back up data, such as date, time, and alarm. 3 Kinds of Adjustable Volumes It has different volume setting to set the alarm lower or higher; 55-70-90DB, Loud-Super Loud-Crazy Loud. USB Powered & Battery BackupConnected with USB cable (excluding the plug) and use 3*AAA batteries (not included) for data backup. When powered only by batteries, the screen will only light up for 10 seconds. Press SNOOZE/LIGHT button to light it up again.