This toolkit can be used do all kinds of cable line installation, inspection and maintenance, and can evaluate the operation of the telephone line in different states, more convenient for telephone line installation, debugging and maintenance work. Avoids damage to cable insulation. Functions: Evaluate the continuity of the cable or wires. Track cables or wires and diagnose a breakpoint. Receive a tone signal on cables or wires (phone line). Indicate the status of the working telephone line (clean, ringtone, busy). Large rear speakers, loud, in noisy environments can also be heard. Intelligence button and indicator light. Effective detection distance of 3000 m. Easy and convenient to use. Specifications: Send Tone Frequency: 1,5 kHz Reception frequency range: 100Hz-300 kHz Receiver Size: 238x43x26 mm or 9,4x1,7x1,0 inch Emitter Size: 145x35x25 mm or 5,7x1,4x1,0 inch Receiver Weight: 56 g or 2,0 oz Emitter Weight: 64 g or 2,3 oz Shell Color: Green Package Size: 300 x 130 x 60 mm or 11,8 x 5,1 x 2,4 inch Package Weight: 261g or 9,2oz List of packages: 1 x Transmitter 1 x receiver 1 x User Manual