OliaDesign 46099 LED Clamp, Black Uses LEDs, which consumes up to 80% Less energy and last 20 times longer than incandescent bulbs.The unit uses USB as its power source Adjustable arm for easy directing of light Slim and lightweight. Easy to place in small spaces and move to wherever you need light Height: 16", clamping range up to 1 1/4" Excellent for college and university students who needs small footprint lights for reading and studying