Multi-function Network Cable Tester RJ45 RJ11 Wire Ethernet Tracer with Audio tonerHigh sensitivity and strong anti jamming ability for identifying the target wire among bunch of wires. Use it to Receiver the tone signal on the cables or wires that include telephone wires (RJ 11), computer network cable (RJ 45). Cable break point can be found easily by tracing cable with receiver and connecting another end with emitter. Sound will change where cable is broken. The device has a light on the top, which makes it convenient to use.