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 port, headphone jack, and on/off knob to provide accurate measurement. High sensitivity metal construction improves sensitivity and sound quality. 3. [Clear Sound] Voice listening detector has excellent sound clarity and can be used indoors or within buildings. Built-in 200mAh lithium battery, compact design, easy to carry. 4. [Easy To Operate] The probe attaches to a variety of piping materials, floors, and walls, allowing you to hear subtle sounds through the headphone that are normally inble. 5. [Widely Used] Ear listening device amplifier is suitable for concrete walls, steel walls, wooden walls, iron walls, glass walls, hollow blocks, and various pipe materials and floors, 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 Li Battery (Included) Operating Temperature: -20°C to 50°C Applicable Surfaces: Cement wall, steel wall, wooden wall, iron wall, glass wall, hollow bricks, and various piping materials and floors Monitoring Method: Headphone, 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 be compared to higher-end models. It is intended for short-term testing only and should be purchased with consideration for more demanding applications.