Features: Wire Tracing Function: quickly find the required line among numerous cables. the instrument is suitable for RJ45 interface cable, RJ11 interface telephone line, and other metal wires. Line Detection & Alignment: for completely testing and detecting the line sequence, the physical connection of the open circuit, short circuit, wrong and reverse connection of the network cable. Telephone Line Status Detection: use the transmitter to test the status of the working telephone line (idle, ringing, off-hook) and discriminate TIP or RING line. Simple & Fast: when searching for cable lines, it is not necessary to strip the line skip, and can determine the position of the line breakpoint. Multifunctional Cable Line Finder: also has functions of line level or positive and negative polarity detection, wire continuous (passage) detection. Earphone & Flashlight: equipped with a pair of earphone for helping wire tracing in the noisy place. Both the transmitter and the receiver designed with a LED lamp for auxiliary lighting in the dark area. Comes with a black bag for storage and conveniently carrying around, really an essential test tool for people who work for telecommunication engineering, wiring engineering, and network maintenance. Specifications: Material: ABS Signal Transmission Distance: Approx. 300m Power Supply: 1 * 9F 6F22 battery(transmitter), 1 * 9F 6F22 battery(receiver) (both NOT included) Operating Environment: 0~40, 80%RH(non-condensing) Storage Environment: -10~50, 80%RH(non-condensing, no battery) Altitude: