You can let the backlight of this clock automatically adjust itself to get dimmer as the room gets darker, or you can manually set the brightness to a constant Off, Low, or High Large LCD display, clean and simple design, and customizable backlight brightness are the hallmark features of this elegant little alarm clock that gives you everything you need in a clock without a lot of confusing extras Gentle wakeup alarm starts out soft and gets progressively louder until you turn it off