The advanced lighting technology incorporated in laptop computers is the amazing 10,000 hour life fluorescent lamp of the Light Voyager Booklight. Most book lights only have a 40 to 50 hour life. The Light Voyager provides an even, cool wash of clean white light over your book, and the steady dual arm design eliminates the "bouncing light" of some booklights. It's a perfect addition for your Levo BookHolder. Use AC/DC adapter, or 4 AA batteries. Batteries not included