Tribotz electronic kit by Elenco features 3 robots in one package. Tribotz Kit uses sensors to avoid objects, follow a line and respond to sound. The Tribotz will react to sound impulses and objects in its way, will reverse away from a sound or obstruction, then move forward. Make a path with a black felt tip marker or black tape and watch how infrared sensors allow the Tribotz to make corrections. No soldering required. Movement: 2 wheels driven by 2 DC motors. Control: sound sensor including condenser microphone, infrared light sources, and light detectors. Tribotz Kit requires 2 AA batteries.