The key thing is what you wrote there: "Sensors Notifon is universal. You can use any sensor that has two states, such as a switch, a push button, a magnetic

The key thing is what you wrote there: "Sensors Notifon is universal. You can use any sensor that has two states, such as a switch, a push button, a magnetic door switch, a relay... Notifon allows you to predefine a set of actions for each state." Just put that (or a simplified form of it - a graphical illustration is helpful) somewhere quite visible on the actual product page?