If you are an electrician, a Voice and Data Technician, an Instrument Technician or a "Do-It-Yourselfer", you need these in your tool box!
Whether you have wires that need to be terminated or you are trouble shooting wire, you need to be sure which wires are which and if they make a full circuit.
HOW TO USE?
Simply hook one phone lead to one of the wires and the other lead to a ground. Hook up the other phone lead to the ground and go through each wire, one by one, until you hear the phones make a connection. Then you can talk to the person on the other end and mark the wire the same on both sides! It's full proof, you can't go wrong! You will save time and man hours!