I have bought almost every book light on the market.  They all take expensive batteries, don't shine bright enough, shine to bright, won't adjust the way I want (hate them all).  This one is perfect!  It takes triple A batteries, I use rechargeable, it also has an adapter with a long enough cord that it doesn't get in the way, it has two settings, light up the entire house and perfect light for reading in bed, and it will adjust any way you want to.  Wish I had found it a long time ago, could have saved me hundreds of dollars.