Sound Tracker Kit Product# MR1001   $39.95  Free Shipping The Soundtracker will react to sound impulses and objects in its way. It will reverse away from a sound or obstruction, then move forward. Kit contains detailed instructions and educational background information on each component used and why. The kit will teach the fundamentals of sensor technology and show you how it all goes together. No Soldering Required. Movement: Three (3) wheels driven by a DC motor. Control: Sound sensor including condenser microphone. Dimensions: 3 3/4" (H) x 5 1/2" (W) x 1 15/16" (L)