KKmoon FY868 Multi-function Wire Tracker Hand-held Cable Testing Tool Two ways to detect connected states of circuits. Use the emitter to detect line level or positive and negative electrode. Can be used for: telecommunication engineer, wiring engineer and network maintenance engineer, etc. Suitable for directly hunting for cables with RJ45 connectors, telephone wires with RJ11 connectors and BNC connectors. Cable sorting is a process of detecting physical connections in a cable like open circuit, short circuit, wrong circuit and reversed circuit.