Fangrui Product Details 1. Bside Fwt81 Rj11 Rj45 Telephone Wire Tracker Toner Ethernet Lan Network Cable Tester 2. Wire Tracking: It Can Quickly Find The Required Line Pairs Among Numerous Ones. It Is Adaptable To Network Cable Rj45 Terminal, Telephone Line Rj11 Terminal. It Can Test Other Metal Wires Via An Adapter. 3. Network Cable Collation: It Tests Physical Connection Status Of Network Cable, Such As Open Circuit, Short Connection, Misswire And Reverse Connection. 4. Line Level, Positive And Negative Polarity Test: Use Transmitter Only To Test Line Level, Positive And Negative Polarity. 5. Status Of Telephone Line Test: Use The Transmitter Only To Test The Status Of Working Telephone Lines. 6. Continuity Checking: This Instrument Can Check The Continuity Of A Circuit. 7. Low Battery Capacity Indication. 8. Battery: 9v, 6f22 Battery(not Included).