The overlay designed for the v3 controller lan, gives the possibility to communicate via GSM network, i.e. send and receive SMS or send data to an HTTP server using GPRS protocol. For operation, an active SIM card of any mobile operator is required. Built-in battery allows you to send notification even in case of power failure.
The overlay does not have simlock - it can be used with any GSM network in range.
To improve the range, mount the antenna outside the metal housing of the controller.