SAR is a robot that uses a sound activated circuit from allelectronics.com to run a 1.5-3vdc motor with a weigth on it to vibrate and move when it hears a sound.Also SAR has three blinking red LEDs for looks and is powerd by two AA batteries.Sar didnt cost much to build all I had to buy was the sound activated circuit and the three red blinking LEDs everything else came from my junk heap. Time to build:one afternoon and about one hour of the next morning. This is my fifth robot to build from scratch. Email: MadCyborgSci@aol.com