This MAYILON telephone wire tracer can be use for variety of cable line installation, inspection and maintenance, and can judge the work of the telephone line in various states, also can be sued for telephone line installation, debugging and maintenance work. Come on and try it, it will not let you down. Features: It can be used for judge the continuty of cable or wires, also can checks diagnose the break point. It can receive the tone signal on the cables or telephone lines, and indentify the state in the working telephone line (clear, ring, busy). Send a sin-gle slid tone solid tone or a dual alternating tone to the object cables or wires. Tail large speakers, sound loud, in a noisy environment can also be heard, give you a better using experience. With the inteligence button and indicator light, easy and convenient for you to use. Specifications: Material: plastics Send tone frequency: 1.5kHz Receive frequency range: 100Hz~300kHz Power supplys: 6F22, 9V (not included) Receiver size: 238 * 43 * 26mm / 9.4 * 1.7 * 1.0in Emitter size: 145 * 35 * 25mm / 5.7 * 1.4 * 1.0in Receiver weight: 56g / 2.0ounce Emitter weight: 64g / 2.3ounce Package size: 300 * 130 * 60mm / 11.8 * 5.1 * 2.4in Package weight: 261g / 9.2ounce Package list: 1 * Emitter 1 * Receiver 1 * Users Manual