Network Cable Tester, Line Finder with Probe Tone, Wire Tracker Blue Product Details Package Dimensions : 8.78 x 4.37 x 1.65 inches; 11.64 ounces Item model number : FY869 Manufacturer : Mastfuyi Country of Origin : China Brand: Mastfuyi Power Source: Battery Powered Style: Analogue Signal Color: Blue Measurement Type: Voltmeter or Ohmmeter ??Cable Sequence Calibration? : It can detect the cable sequence, open circuit, short circuit, wrong pair and reverse connection of the network cable ??RJ45 RJ11 Cable Tracking? : RJ11 and RJ45 cables can be found through transmitter. It is simple and fast to find the line without stripping the outer skin of the cable ??Telephone Line Status Detection? : It can detect the status of the working telephone line (idle, ringing, off-hook) and discriminate TIP or RING line ??Detect Cable Level and Positive and Negative Polarity? : Use the transmitter to detect the DC level or positive and negative polarity of the line ??Transmitter Undervoltage Indication? : Rotate the function knob of the transmitter to the ?SCAN? position. When the transmitter's battery is lower than the working voltage, the cable finding function indicator ?SCAN? on the transmitter will flash. When the indicator is flashing, please Replace the battery in time ??Cable Connectivity Detection? : Only transmitter can be used to detect the connection status of the cable ??3.5 mm Headphone Jack? : The 3.5 mm jack allows for headphones to be attached in noisy environments ??Receiver Undervoltage Indication? : Turn on the power of the transmitter, press and hold the receiver ?SCAN? button to bring the probe to the RJ45 connector of the transmitter, and adjust the volume adjustment knob of the receiver to the maximum volume position. If no sound is heard from the receiver or When you have a small sound, please replace the battery in time ??Package Content? : 1 x Transmitter, 1 x Receiver, 1 x Earphone, 1 x RJ11 Converter Interface, 1 x RJ45 Converter Interface, 2 x 9V Batteries, 1 x User Manual