Feature: 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, walls, 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. 4. [Easy To Operate] The probe can be attached to a variety of piping materials and floors, pipes, walls; you can hear subtle sounds through the earphone that are normally inble. 5. [Widely Used] Ear listening device amplifier is suitable for concrete wall, steel wall, wooden wall, iron wall, glass wall, hollow blocks, etc., and various pipe materials and floors, walls, etc., to meet your needs. Specification: Item Type: Through Wall Microphone Material: Plastic, Electronic Components Product Size: Approx. 61 x 35mm / 2.4 x 1.4in Current Consumption: 10mA Battery: 200mAh Lithium Battery (Included) Operating Temperature: -20°C to 50°C Applicable Surfaces: Cement Wall, Steel Wall, Wooden Wall, Iron Wall, Glass Wall, Hollow Bricks, etc., and various piping materials and floors, walls, etc. Monitoring Method: Earphone, External Speakers Can Be Connected Package List: 1 x Through Wall Microphone 1 x Earphone 1 x Data Cable Note: 1. Manual measurement, please allow slight errors. 2. This detector is a basic home-use model and its sensitivity cannot match that of higher-end models. It is intended for simple, short-term testing and should be purchased with caution for professional or demanding applications.