【Ideal for Cable Installation & Maintenance】Perfect for installing, debugging, and maintaining telephone lines and various other wires or cables. 【Non-Damaging Cable Detection】Detects cable continuity without causing any damage to the insulation, ensuring safe use. 【Cable Tracking & Breakpoint Diagnosis】Easily track cables and wires and diagnose break points for efficient repairs. 【Tone Signal Detection】Receives tone signals on cables or wires, including telephone lines, to identify the state of the connection. 【Dual Tone Functionality】Sends a single solid tone or a dual alternating tone to the cables, helping with precise identification and tracking. 【Portable & Professional Tool】Includes an emitter and receiver with a convenient carrying bag, making it a professional and portable tool for wiremen. Specifications: Send tone frequency: 1.5 kHz Receive frequency range: 100 ~ 300 kHz Power supply: 6F22 (9V) Battery (Not included) Receiver size: 23.8 x 4.3 x 2.6cm Emitter size: 14.5 x 3.5 x 2.5cm