This is a novelty inductive car, which follows the marker line like magic. If you place the Inductive car somewhere else it would run in circles until it finds the line. The Toy has an optical sensor that reads the black line drawn on a white piece of paper. The car is powered by 4 x AG 13 button cell. Marker pen included. The line thickness should not under 4mm and not overrun 10mm, Non sharp-angled line. Will make Perfect gift for your little child.