Description: HY929 High Strength Wall Microphone Voice Listen Detector for Engineer Water Leakage Oil Leaking Hearing for Repair wooden walls, doors, windows, steel plates, etc. Highly Sensitive, carefully adjust audio slowly, as cause discomfort to your earbuds. This audio by amplifying the vibrations of audio. When people are talking in their voices are waveband, and depending on how loud they are talking, the waveband travels long distances which are picked up and amplified by this device. The volume of adjusted, including probes, probes, built in batteries, etc., which can be used repeatedly. This being an investigative tools for law enforcement or licensed investigators Specification: Model: HY929 Material: ABS Metal Current Consumption: 10mA Battery: Lithium battery 3.7V batteries Probe Sensitivity: 10 db Maximum Audio Magnification: 20000X Answering method: Headphones ohm speakers Size Chart: Size: approx. 6x4x2cm /2.36x1.57x0.79inch Package Includes: 1 Piece Detector 1 Piece Plug (UK) 1 Piece Circular probe 1 Piece Needle probe 1 Piece USB Cable 1 Piece Headphone 1 Piece Manual Note: 1. Please allow slightly error due to manual measurement. 2. Due to between different monitors, the picture may not reflect the actual the item. 3 shopping!