The Lisle Corporation Digital Test Light with Load Tester, No. 28800, is a 3V to 30V DC dual polarity digital test light that can also apply load to get an instant voltage drop reading. The light works as a regular test light, but when the button on the tool is pushed it applies an 800mA load at 12V DC to easily check for voltage drop on circuits. It include a 48" cord with heavy duty alligator clamp for secure connections. Not computer safe with load applied and not for use on airbags.