Description: *High precision and work efficiently. Wire tracing for RJ45, RJ11 telephone line and other metal wire in low electricity. *It is a neceary testing tool for telecommunication engineering, wiring engineering and network maintenance person. *Multi-functional handheld cable testing tool that is so easy for using. Help to test line level, positive and negative polarity. *It can use for status of telephone line checking: Test the working status of telephone line (idle, ringing, and off-hook) and judge TIP and RING line. *Wide range of applications with reinforced cable types and multiple functions. Check the cable continuity function, a complete detection of the network cablesequence, short circuit, circuit, wrong, reverse. Specification: Item type: Wire Tracker Receiver Size: 205x40x30mm Emitter Size: 125x65x30mm Color: Blue Brand: BSIDE Model: FWT11 Power: 2X 9V 6F22 battery Operating temperature: 0 C ~ 40 C, maximal 80% relative humidity (non-condensing) Storage temperature:-10~50C, maximal 80% relative humidity (non-condensing, battery not included) Altitude: