The General Technologies CT8002 cordless computer safe, all solid state electronics circuit tester is safe to use around automotive computers, electronics, ECMs, sensors and air bags. Rugged, built to last and simple to use, the CT8002 requires no wire or clip connector to ground. With LED, sound and vibration indicators, users can check for power in less time that it takes to setup a regular test light and find a suitable ground. Designed for use with any DC-powered circuit from 3V to 28V.