Fangrui Product Details 1. Bside Fwt11 Rj11 Rj45 Telephone Wire Tracker Ethernet Lan Network Cable Tester Detector Line Finder 2. This Instrument Is A Multi-functional Handheld Cable Testing Tool. It Has Wide Application With Reinforced Cable Types And Multiple Functions. 3. It Is A Necessary Testing Tool For Telecommunication Engineering, Wiring Engineering And Network Maintenance Person. 4. Work When Rj11rj45 Cable Is On Power 5. Wire Tracing: Trace Rj11, Rj45, Cables Or Other Metal Wire (via Adapter). 6. Easy And Fast To Locate The Break Point Without Opening The Wire's Cover. 7. Network Cable Collation: Judge Short-circuit, Breaking Circuit, Open Circuit And Crossing. 8. Test Line Level, Positive And Negative Polarity. 9. Status Of Telephone Line Checking: Test The Working Status Of Telephone Line (idle, Ringing, And Off-hook) And Judge Tip And Ring Line. 10. Check Wire Continuity.