The ideal device for checking the continuity of wiring, fuses, switches, relays, etc. The bright flashing LED light and loud pulsating beeper provide positive continuity checks in a noisy working environment. The pocket sized device is light enough to be suspended by the attached alligator clip connections. No need to prop it up. Allows hands-free operation.The Continuity Tester Pro can also identify wire pairs or multiple cables remotely by using the external probe. The probe's bi-color LED light will flash green or red depending on polarity. Can be used to label and identify up to three cables with only one trip to the end location -cuts down on multiple trips back and forth.