Tracing cable lines, as well as identifying the location of a broken circuit. Receive audio in the cable line (telephone line), determine the status of the working telephone line (idle, ring, go off-hook).Send a single audio or to the cable line. Feature - Color: Blue - Material: Plastic+Electronic Component - Size: 20.5 x 6.4 x 3cm - Battery supply: 6F22/9V (Not included) - The cable tester kit with quickly detect the continuity of cable line. - The wire can accurately track the cables or wires and diagnose the of cables. - This telephone line tester is able to identify the state of a working telephone line ( clear ring, busy ). - This rj11/ line is very easy install and operate so that anyone even with no experience can use it to test wires. - The professional wire test tool include a sender and a receiver. Package list: 1 set of Line