The way this inexpensive Humvee Elite Shaker Light works is by shaking it. When you shake the flashlight it recharges itself so there is never any need to worry about batteries and them dying. There are three ultra bright LED light bulbs in the flashlight. You can used a single LED light or all three. An LED light is guaranteed to last 100,000 hours. The flashlight itself is nine inches in length. It is also waterproof which is great for keeping one on the boat or in the garage. The next time you are looking to purchase a flashlight that will shine bright then look at this inexpensive Humvee Elite Shaker Light.