Portable LED Pocket Book Light with Adjustable Angle - Red PORTABLE LED LIGHT : Bright LED casts ample light for reading in dark environments. BATTERY: Bright LED bulb that is powered by three replaceable LR41 button cell batteries (included and pre-installed). EASY TO ADJUST: There is a hinge in the center that allows the light to be adjusted for the perfect angle while it rests on the book cover. USE : Great for reading books, maps, newspapers, and more. Clips onto book cover, clipboard, shirt pocket, etc. SIZE: Lights measure 5" long and approximately 1/2" wide.