The Energizer LED Book Light Is Lightweight And Can Broadcast 14 Lumens Of Light. The Flexible Rubber Neck Bends Easily And Holds Its Position For Precision Lighting. Features A Wide Angle Nichia LED Providing A Wider And More Evenly Broadcast Of Light. The Oversized Spring Clip Easily Attaches To Books, Kindles, Clipboards, And Even Car Visors. The Replaceable Lithium Coin Cells Provide A Long-Lasting 10 Hours Of Continuous Reading.