1. The GSM telephone circuit board is great for placement where there is no telephone cable.
2. It can be configured and managed remotely through an SMS application with a 3G /4G sim card,
purchased from any network provider.
3. 2-way auxiliary relays are available.
4. Voice interface: hands-free, handset, audio interfaces, and an external amplifier interface.
5. Power supply: AC 110v/220v power or built-in rechargeable battery with solar-powered panel optional.
6. This GSM telephone PCB supports message function for low battery, door opening & low signal strength.
7. Lightening protection to ITU-T recommendation K.21.
