One of the most useful products I have ever purchased - I own three.  I use it every night - never have to buy another battery for it as long as I use the cord.  At first I purchased the light without the cord but I was going through batteries like crazy.  I have a Kindle Fire but I don't prefer to read books on it due to the back light.  I use my Kindle Keyboard and of course I need a light to read by.  This one is absolutely perfect for my use.  I read about 10-12 books each week.