MULTI-TASK CABLE TESTER: The handheld ethernet cable tester supports you to find the target line in complex networks quickly. This cable finder tone generator is an ideal wire tracker for your , such as telephone line cable testing, network cable tracing, TV cable and other weak current electric wires. NETWORK CABLE TESTER: Plug the cable into the RJ45 terminal, the other end into the receiver. Select "TEST", indicator light on means the cable is connected. This Ethernet Cable Tester is a multifunctional handhold network tester can help you track network cables even in complex electrical networks. TELEPHONE LINE TESTER: 5900A Toner Tracker can accurately test the working status of telephone line (idle, ringing, and disconnecting). Plug into the RJ11 terminal for telephone line checking. WIRE LINE : This network cable tester can fully test sequence of network cable, open circuit, short-circuit, miss wiring, error connection and reverse connection; Test line level, positive and negative polarity. EARPHONE INCLUDED: Built-in bright Lamp and Earphone to enable you'll use tester conveniently and comfortably in dark and noisy environment. Basic Function: RJ45 network cable searching RJ11 telephone wire searching BNC coaxial cable searching Wire breaking faults testing Line level or positive/negative pole test: DC voltage, test positive/negative of DC volt in the RJ11 wire Telephone wire status testing: TIP RING Hunting, RJ11 telephone line status testing(idle, ringing, on hook) Status for network cable connected to the switch postNetwork cable error checking: short circut, connection error, reverse connection, crosstalk error. Why for BT-5900A Wire Tone Generator? Accurate & Easy to operate: Well made by CNC machining technology, each port has ched standard, this network tester can accurate help you with the cable searching, test result shows by indicator light and sound, friendly use in noisy or dark environment. Transmitter Power Supply:3 x 1.5V(AA) battery (Not included batteries) Receiver Power Supply:1 x 9V(6F22) battery (Not included batteries) Color:As Shown Material:plastic Package Contents: 1 set * network cable testers Only the above package content, other products are not included. Note: Light reflection 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.