Features:

1. It can store 64 user telephone numbers; these numbers are entered into the controller, do not need to be connected, automatically hang up, and the relay is closed once;

2. You can use the command to set all the incoming calls to control the controller, but you can also use the SMS command to set only the numbers already stored in the controller to control;

3. After the call, the controller automatically recognizes whether it is the number already stored in it, if it is, the relay is closed, if not, it will not open unless it is set to a function that all phones can control;