The “Large 9” LED display alarm clock” is huge. Each digit is 3” high, certainly bigger than most clocks in the home. You set the time, alarms, snooze, etc. with UP and DOWN arrows near the top of the clock. The back of the clock features two USB 5V 1A charging ports for charging small devices like smartphones. A dimmer setting can be adjusted for the brightness you prefer for sleep. Dual alarms mean you can set two separate wake-up times. A snooze button on the top allows you to have 5-60 minutes (you set that too) more to stay in bed before the alarm sounds again. All functions work under AC power, the backup battery (included) is for a memory function to back up time and alarm settings in case of AC power failure. There will be no display digits on the clock if the power goes out. But when the power comes back it will remember all your settings. Under $26.00 as of 10/20/18.