1. [Multi Application] High strength through wall microphone can be used for pipe side leakage, floor heating detection, and water detection. Applicable to various pipeline materials and floors, wall, etc. 2. [Multi Functional] Through wall microphone amplifier is fully functional with charging hole, earphone hole and on off knob to provide accurate measurement. High sensitivity metal arrangement improves sensitivity and sound quality. 3. [Clear Sound] Voice listening detector has excellent sound clarity and can be used anywhere, even indoors or in buildings. Built in 200mAh lithium battery, compact design, easy to carry. Specification: Item Type: Through Wall Microphone Material: Plastic, Electronic Components Product Size: Approx. 61 x 3.5mm / 2.4 x 0.1in Current Consumption: 10mA Battery: 200mAh Lithium Battery (Included) Operating Temperature: -20℃-50℃ Applicable: Cement Wall, Steel Wall, Wooden Wall, Iron Wall, Glass Wall, Hollow Bricks, etc. And Various Piping Materials and Floors, Wall, etc. Monitoring Method: Earphone, External Speakers Can Be Connected How to Use: Use after charging PackageList: 1 xThrough Wall Microphone 1 x Earphone 1 x Data Cable Notice: 1. Manual measurement, please allow some errors.2. This detector is a simple home version and its sensitivity cannot be compared to more expensive products. It can only be tested briefly and must be purchased with caution for more demanding requirements.