Our book light is sleek, compact and perfect for travelaand has an astonishing 100,000 hours of bright light. Hemingway in the afternoon, Updike after hours, and Melville until morning. This clip-on light provides 10 years of bright, well-lit reading. Revolutionary LED (light emitting diode) bulb uses less energy, remains cool to the touch, and evenly distributes light to reduce eyestrain and fatigue. Lightweight, compact design folds for travel.