1. USB Mode Switch to the USB direction plug USB cord and light up the pad.you can not only plug it into the wall charger but also your computer 2. Battery Mode Switch to the battery direction and light up the pad. Tips: In battery mode you can connect the USB cord to charge.The light pad can work continuously about 2 hours after 1.5 hours' charging. 3. Adjustable Brightness. With the adjustable dimming feature you'll have control of the light by simply pressing on the power button until it is the brightness you need. 4. Smart-Memory. When you finish your work and turn off the light pad it can memorize the brightness you set and it will be the exact light you need when you turn on again.