The 1.8 inches large numbers on this 6.6 inches compact alarm clock are super easy to read from across the room, no complex setting, easy to program, which is an ideal desk clock for kids, seniors, the elderlys and adults. The display brightness of this digital clock is 5 level adjustable plus an OFF option, which is vision friendly, no glaring light at night yet still bright enough by day. The display brightness of this digital clock is 5 level adjustable plus an OFF option, which is vision friendly, no glaring light at night yet still bright enough by day. The display brightness of this digital clock is 5 level adjustable plus an OFF option, which is vision friendly, no glaring light at night yet still bright enough by day. The bedside clock runs on electricity for normal time display and the AC adapter is supplied. A handy USB Charging Port helps you charge your smart devices and other gadgets without looking for your adapter and other outlet.