e, the upgrade amber book light blocks 99.95% blue light, will not stimulate your photoreceptors or disrupt circadian rhythm while using it in bedroom. Effectively protects your eyes from being damaged by blue light when reading. 【USB Rechargeable】Easily Charged with built-in USB, directly plug it into your laptop, power bank, adapter, car charger, or USB outlet for recharging, no additional cables needed. 200mA lithium battery, 1.5 hours charging lasts about 8 hours(at brightness setting). No more wasting money on batteries. 【3 Brightness Levels】30%, 60%, 100% brightness available, allows you to choose the perfect brightness to keep your eyes comfortable, enjoy your time reading in bed without disturbing your roommate. Short press to switch the brightness, long press to turn the book light off.Brightness memory function, it will remain the brightness level you selected before. 【Compact...