[ ] This small reading light has 5 brightness levels available, you can choose the most suitable level for your eyes. You can set your favorite brightness as default with the book light for reading in bed. Plus, there are 5 LED beads scientifically installed so the light can be evenly distributed on reading pages. It is bright enough to illuminate the full pages, while it is dim enough not to disturb others nearby. No flickering, nor harsh light. [ & ] Unlike other reading lights for books, our tiny reading lights for books in bed has 3 different reading modes: amber mode(1800K), breeze mode(3400K), and precise mode(6000K). Amber mode filters 99.9% blue light to protect your eyes and reduce your eye strain. The breeze mode provides you with a cozy and comfortable reading world for novel reading & poem reading. The precise mode highlights the area clearly and so you can concentrate on every detail of your book. [ & ] Standard USB rechargeable and compatible with any USB ports on your computer, adapter or USB outlet. This rechargeable clip on book reading light has a built-in 500mAh battery providing you with 1080 reading hours (depending on your brightness setting). So you can enjoy your reading for 20 days to 3 months if you read 30 minutes per day, based on your light setting. Besides, there are 4 power indicators to show the power leftover. [ & ] The clip on light can open maximally 150; the light head can be turned left, right and downside with angles of 90, 90, and 45 respectively. It is flexible enough for all book sizes. You can adjust the angles freely to get comfortable lighting. This rechargeable book light is only 1.41oz(40g), much lighter than an egg. Its lightweight and small design make it have air portability or clip on books without much effort. Perfect tiny book light for traveling.