Features: 1.Cable Testing: This wire tracer can test physical connection status of network cable, such as open circuit, short connection, miswire and reverse physical connection. 2.Support Earphone: This circuit tracer is equipped with a headphone jack, you can simply connect the headphone to headphone jack to get clear information in the noisy environment, adjust the volume knob to keep the volume appropriate and avoid interference. 3.Wide Application: This Ethernet tester is very suitable for tracking RJ11, RJ45, network cable, telephone line, single wire, optical fiber line. Use the emitter to test the status of working of telephone lines (such as judging TIP or RING line) 4.Hard Shell: This network cable tester with smoothing appearance and flexible interface adopts sturdy and durable ABS material, which provides safer protection. 5.Necessary Tool: This wire tracer is necessary testing tool for telecommunication engineering, wire engineering and network maintenance person. specification:Item Type: Wire Tracer Material: ABS Power s: DC, 9V Laminated Battery x 2(Battery Not Included) Signal Transmission Format: Multi Frequency Pulse Test Cable: Twisted Pair Cable, Telephone Line, Video Line, Common Metal Wire, Network Cable Testable Interface :RJ11, RJ45 Signal Output Level :8Vp p Signal Transmission Distance: 1 to 3000 Meters / 1.1 to 3280.8yd PackageList:1 x Set of WireTracer(2 Accessories) 1 x User Manual 1 x Earphone Cable