T Tocas Large Big Number LED Snooze Wall Desk Alarm Clock Thermometer Date Display (Blue) Function:Led Clock,Thermometer( to F),Calendar,Alarm,Luminous,Snooze Long-distance readable. it is readable easily within 25 meters, which is very different from traditional clocks Notice: Power Supply by Plug, input AC100-240v, Working voltage: DC7.5v. Button cell(CR2032) back-up, battery just for keeps the time correct when the clock is unplugged but DOES NOT keep the figures lit the LED brightness can be adjusted. It can be used as a table/desk clock, but also can be hung to act as a wall clock It can be used as a table/desk clock, but also can be hung to act as a wall clock.