Happy Hours&reg; Digital Voice Sound Control Activated Wood Grain Soft Night Light LED Alarm Wooden Clock Desk Despertador USB/AA Battery Powered Calendar Temperature Display,White Wood+White LED LED display, easy to view even at night Celsius and Fahrenheit display of thermometer. To lock time display through setting It also works in voice mode. Make some noise (clap your hands, rap on the table or pat the clock) nearby can wake you up. We recommend to use USB cable to support the power. The clock worked with battery can only last about 2-3 days.