This cyber bug possesses a sonic tracking system, and is fortified with amultitude of sensors: photo transistors to detect a black line, tracking memory to memorize its last track of the black line, and two red LED'sthat to tell you which side of the light sensor is activated.Hyper Line Tracker follows a designed course. By using an infrared emitter, light sensor circuitry, and tracking memory, it demonstrates how robots see a pathway. Make a path with a black felt tip marker or black tape and watch how infrared sensors enable the robot's motors tomake course corrections. Printed circuit board pre-assembled. Requires 4 AA batteries.