Features: High-strength wall-mounted microphone voice hearing detector, used for engineers to hear water leaks and oil leaks, and used for maintenance projects such as wooden walls, doors, windows, and steel plates. Monitoring mode, headphone jack, external speakers Highly sensitive, adjust the audio carefully and slowly so as not to cause discomfort to the headset. This audio device works by amplifying the vibrations of the audio. Small size, easy to carry. The high-sensitivity sensor head adopts new components and advanced technology to increase the penetration by several times, and the sound quality is greatly improved. Effectively filter noise. Adopt advanced technology to effectively filter noise and detect water outlet faster. When people speak in a room, their voice is just a band that travels short and long distances, depending on how loudly they speak, and is picked up and amplified by the device. This product is sold as an investigative tool to law enforcement or licensed investigators. Specification: Probe Sensitivity: -60Ddb Answering method: 32 ohm earphones. Material: plastic + electronic components Size: 3.6x3 5mm (approx.) Current consumption: 12mA Battery capacity: 100mAh Battery life: 4-6 hours Working temperature: -20°-50° Colour: Black Notice: The detector is a simple home version, and the sensitivity cannot be compared with expensive products. It can only be tested simply, and those with higher requirements should purchase carefully. Due to different monitors and lighting effects, the actual color of the item may be slightly different from the color shown in the pictures. Thanks! Please allow 1-2cm measurement deviation due to manual measurement.