Extech Remote and Local Continuity Tester. One person operation for wire and cable testing: Local continuity checking is accomplished by a bright flashing LED and loud pulsating beeper. Remote continuity with the use of the remote probe, it does not tie-up two people when identifying and labeling long distance wire/cable runs. Flashing remote probe - two lead, bi-color (red/green) LED probe allows a single user to identify up to three wires or cables at a time for correct labeling with only one trip to the other end location - cuts down on multiple trips back and forth. Lightweight and pocket-sized, clips on and hangs from the cable(s) under test without falling off. Great from Electricians and Helpers, Cable TV and Audio System Installers, Alarm Technicians, Plumbers, HVAC Installers, Auto Repair Technicians, Carpenters, Handymen, and Do-it-yourself Homeowners.