1、Easier Testing: When used with any tone generator, the volume adjustable wired tone probe kit can identify and track wires or cables within a group without damaging the insulation. 2、Safe for Using: The method is simple and the test result is accurate. Insulated probes and built in speakers can effectively avoid conductor short circuits, making it safer to use. 3、Function: The circuit tester has a spring loaded on and off button, also has sensitivity control on volume adjustment, embedded terminal port for mobile phone connection, resistance plastic carbon fibre tip to prevent accidental short circuit when detecting wires. 4、Broad Utility: Widely used for the maintenance of cables and wires. The measurement area includes line tracking, short circuit test, ringing recognition, and measurement on non terminal cable, telephone and network lines. 5、Advantages: This tone and probe kit are made of good materials, wear resistant and corrosion resistant. The gain is normally 30dB, and the input impedance is nominally 100M Ohm. Please note that the line controller requires one 9V batteries, which are not included. Item Type: Tone Finder Material: ABS Shell Gain: Nominal 30dB. Input Impedance: Nominal 100M Ohm. Probe Resistance(Minimum): Metal tip: 0 Ohm, plastic tip: 300 Ohm. Battery: 1 x 9V battery (NEDA 1604, JIS 006P, or IEC 6LR61) (Delivery without battery) Temperature: Celsius: 0℃-50℃, Fahrenheit: 32℉- 122℉. 1 x Tone Finder (2Pcs Part) 1 x Replacement Head 1 x Storage Bag 1 x User Manual