Feature: 1. Sound Sensitivity: Align with the high sensitivity metal of the earphone to improve sensitivity and sound quality. More convenient use experience. 2. Powerful Function: The function is compact and complete, with charging hole, earphone hole and up switch knob. Humanized design, easy to use and adjust. 3. Excellent Sound Clarity: It can be used anywhere, even indoors or in buildings, and has a built in lithium battery, which is easy to operate and carry. 4. Easy to Operate: The sound can be made of wood coaxial, window, door or armor plate. Has good compatibility. 5. Wide Application Range: It can be used for pipeline side leakage/floor heating detection/water body detection. Suitable for all kinds of pipeline materials, ground, pipelines, etc. How to Use: Take out the product and use it Specification: Item Type: Sound Amplifier Material: ABS Colour: Black Battery: Lithium Battery (Included) Battery Capacity: 200mA Parameters: Widely Used Sound Reinforcement Device, Suitable for Various Positions Package List: 1 x Sound Amplifier 1 x Headphone 1 x Micro SUB Power Supply Line