ROAD GENIE: 12V Emergency Light With Powerful Magnet Light is 2-1/2 inches in diameter, and 2-3/4 inches long. More than 9 feet of cord is accessable by twisting the black ring on top Bottom Is Hinged So Light Can Be Adjusted While Magnet Holds Fast Single bulb with large reflector to provide the light you need in an emergency Power cord plugs into your accessory outlet and is powered by your car battery