Features: Works perfectly when RJ11 RJ45 cable is on power. Trace RJ11, RJ45, cables or other metal wire (via adapter). Easy and fast to locate the breakpoint without opening the wire's cover. Network cable collation: judge short-circuit, breaking circuit, open circuit and crossing. Test line level, positive and negative polarity. Status of telephone line checking: test the working status of telephone line(idle, ringing, and off-hook) and judge TIP and RING line. Check wire continuity. Specifications: Work Temperature: 0~40Cthe maximum 80% relative humidity(no coagulation) Storage Temperature: -10~50C, the maximum 80% relative humidity [no coagulation, no battery] Altitude: 2000 meters Anti-explosion Rating: IP40 Distance of Sending Signal: 100 meters Battery(NOT Included): Emitter: 1 * 6F22/9V Battery; Receiver: 1 * 6F22/9V Battery