The LED Forever Flashlight uses the Faraday Principle of Electromagnetic Energy that guarantees replacement parts will never be needed! 15-30 seconds of shaking provides up to 5 minutes of continuous bright light! Product Highlights: • Dimensions: 7 3/8" Long x 1 3/4" in diameter • Super bright Blue LED light • Never needs batteries • Never needs bulbs • Waterproof • Visible for over a mile • Great for cars, boats and campers and all emergency kits.