Made of high quality materials, durable, wear-resistant, corrosion-resistant. Sonda insulating and built-in speaker can effectively avoid short circuit of the cable and make it safer to use. Measurement areas include line tracking, short-circuit testing, spacing/business/ringing recognition. In the case of indefinite cables, clamp mode can be used do direct measurements, as well as do measurements of telephone and network lines. With optional continuous or adjustable generator, the method is simple and the test results are accurate. It is widely used in cable and wire maintenance. Specification: Material: plastic; Gain: nominal 30dB Input Impedance: Nominal 100 M Ohm Probe tip resistance (Min): Metal Tip: 0 Ohm Plastic Tip: 300 Ohm Battery: 1 battery 9V DC (NEDA 1604, JIS 006P or IEC 6LR61) (battery not included) Battery life (nominal): 50 hours Temperature: Celsius: 0 - 50 Fahrenheit: 32- 122 Weight: Approx. 300g/10,6 oz Size: Approx. 231x55x28mm / 9,1x2,2x1,1 inch List of packages: 1 x do storage bag 1 x tester cables (2 pieces) (battery not included) 1 x User Manual 1 x Replacement Head