This is called the RevoPower Wheel it turns your regular pedal powered bicycle into a Gas Powered Bicycle. It is a cheap and easy way to get about without the sweat and effort although it does defeat a big chunk of reasons for riding s abike in the first place! It consists of a 25cc two-stroke gas-powered engine and gears within the front wheel of a bicycle. This system can fit onto any 26" wheeled bike. Not bad!