Perfect for installing, debuging, maintaining telephone line and other wires or cables. Detect continuity of the cables or wires without damaging the insulation. Track the cables or wires, and diagnose the break point. Receiver the tone signal on the cables or wires (telephone line). Identify the state in the working telephone line (clear, ring, busy). Send a single solid tone or a dual alternating tone to the object cables or wires. Include a sender (MS6812-T) and a receiver (MS6812-R). A profeional & safe tool for wireman. Specifications: Send tone frequency: 1.5kHz Receive frequency range: 100 ~ 300kHz Power supply: 6F22 (9V) Receiver size: 23.8 x 4.3 x 2.6cm Emitter size: 14.5 x 3.5 x 2.5cm Receiver weight: 106g Emitter weight: 114g Package size: 25.5 x 12 x 4cm Package weight: 371g package : 1 * Sender 1 * Reciever 1 * Pouch 100% Brand new.