The Hercules consists of a powerful drive unit with a built-in motor, controller, and magnetic sensor. It travels on a flat surface to create curve or straight dolly shots, and a 24″ slider track with adjustable feet is included for shooting on any surfaces as well as on a tripod. When you place a magnet (included) on each end of the slider track, the dolly will move until it senses the magnet then ramps down softly. Once it comes to a complete stop, it pauses, then it ramps up in speed slowly until the programmed speed is reached. The Hercules travels continuously between the two magnets until you pause the device.