Follow Any Drawn Line Pen Inductive Robot Model Kids Toy Gift for Children Feature: 100% brand new and high quality. Quantity: 1PC This is a novel inductive car that follows the marked line. If you place the inductive car elsewhere, 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 paper. The car is powered by 4 x 13 button cells. Marker pen included. The line thickness should not be less than 4 mm and not exceed 10 mm, and should not be a sharp-angled line. Will be a perfect gift for your little child. How to play: Use an ordinary dark-colored crayon or marker to draw a line on a white paper. Turn on the switch on the car's button. Place the car on top of the drawn line. The robot will run on the line automatically. If the line ends, the vehicle will continue in the direction followed from the previous line. If the line is too thin, the vehicle may stray from the line; please make the line thicker (the line should be a quarter inch thick). Package Content: 1 x Robot 1 x Pen