Feature:1. High Quality Material: Ear amplifier is made of high quality ABS material, high strength, wear resistant, sturdy and durable.2. High Sensitivity: Audio listening wiretap device has high sensitivity, clear audio, and you can use the earphone to improve audio quality.3. Complete Function: With charging hole, earphone hole and upward switch knob. Humanized design, more practical and convenient.4. Easy Operation: Sound amplifier can be used anywhere, even indoors or in buildings, and has a builtin lithium battery, easy to operate and carry.5. Application: Audio ear listening device can be used for pipeline side leakage, floor heating detection, water body exploration.Specification:Item Type: Audio Listening Wiretap DeviceMaterial: ABSBattery: 3.7V lithium battery 150mah (built-in battery)USB Charging: 5V.Package List:1 xAudio Listening Wiretap Device1 x Earphone1 x USB Cable