Feature: 1. Automatic monitoring function, as long as the normal exceed 40dB volume iswithin 10 meters, the product will start an alarm, it will automatically call back, dial or send a text message to the bound number in turn. 2. You only need to dial the number of the SIM card installed in the device, then you can hear the sound within 10 meters near the device within a few seconds. 3. Professional dual microphone design, the two microphones can work independently or cooperate with each other. HD sound quality, imported voice chip, seamless intercom. 4. Support for setting multiple groups of numbers, the device will call back one by one, and there will be no errors or omission of emergency feedback, support for private rights protection, only the bound number can be operated. 5. Various ways to alarm, SMS and phone call, SMS mode always keeps the attention, will intermittently remind the host's voice status. 6. Can be applied for car anti‑theft alarms and home monitors, with good safety protection devices. 7. Small and lightweight design, easy to hide or carry. High‑quality ABS material, durable, hard, not easy to break, and long service life. Specification: Condition: Brand NewItem Type: GSM Audio MonitoringMaterial: ABSColor: BlackVoltage: 100-240VPower Supply: 450mAh Lithium Battery (Built-in) Number of Microphones: 2 Effective Range: Approx. 10m/10.9yd Working Mode: SIM GSM Working Frequency: 850mhz, 900mhz, 1800mhz, 1900mhz Standby Time: 4-5 Days with Voice Control, 5-7 Days Without Voice Control Product Size: Approx. 4.4 x 3.3 x 1.3cm/0.05 x 0.04 x 0.01inApplication: For car anti-theft alarms and home monitors, with good safety protection devices. Package List: 1 x GSM Audio Monitoring 1 x USB Cable1 x Power Plug1 x Sticker1 x Instructions