This Cable Tracker is designed to identify and trace wires or cables within a group without damaging the insulation. For telephone line, it can identify some states in the line. With this instrument install, debug, and maintain telephone line is more convenient. A Sender and Receiver is included in the Cable Tracker.Color: yellowMaterial: ABS+ metalApplication:Testing polarity of phone linesTracing a wireFinding wires buried behind drywallTest whether a cable is interruptedFind interrupts in cableCompatible with all common tracing tone sourcesJudge continuity of the cables or wiresTrack the cables or wires, and diagnose the break point.Receive the tone signal on the cables or wires (telephone line)Identify the state in the working telephone line (clear, ring, busy)Send a single solid tone or dual alternating tone to the object cables or wiresReceiver:On/Off buttonTest button3.5 mm earphone jackSender:Tone/Off/Cont (Continuity) switchTone/Cont (Continuity) LEDsRed and black test leads cable (61cm length, approximate)Built-in RJ-11 telephone cable (47cm length, approximate)Receiver Dimensions: 23 x 4 x 2.3cm (H x W x D, approximate)Sender Dimensions: 6.5 x 5.6 x 2.1cm (H x W x D, approximate)Power : 9V battery (6F22) Not includedPackage Contents:5 x Cable Tracker Sender5 x Cable Tracker Receiver5 x Carrying Pouch5 x English User ManualOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.