Multi purpose Sound Control Backlight Digital Alarm Clock Thermometer Hygrometer Features: Support 12 or 24 Hours Display: This digital alarm clock support 12 or 24 Hours selectable time display format, you can choose the time display format you want. Sound control backlight function: You can turn on the backlight by pressing the LIGHT key or clapping your hands or patting the desk and the backlight will last for about five seconds for easy reading(Within 1 meter) Alarm clock and snooze function: You can preset the time to wake you up. Dual Power Supply: Powered by USB cable or 4 pcs AAA batteries (not included). Multifunctional display: Displays time, temperature(℃/℉ switchable) and humidity at the same time. This desktop digital alarm clock suits for home & office. Specification: Material: ABS Color: As picture  Power supply: 2*AAA battery（Not included) Temperature measuring range: 0-50℃（32-122℉) Calendar: 2000-2099 Size: 9.6*9.6*4cm / 3.78*3.78*1.57inch(Approx.) Package list: 1 * Digital Alarm Clock(Battery not included)  1 * User Manual Notice: Please allow 1-3cm error due to manual measurement and make sure you do not mind before ordering. Please understand that colors may exist chromatic aberration as the different placement of pictures.