The door and window contact is simply attached to a door, window or even a cupboard. When the relevant object is opened or closed, the contact sends a signal to the Smart Home central unit.
If required, the door and window contact will send a notification when a change occurs, reliably informing you of any unauthorised access. It is also possible to trigger a programmed scenario. If a window is opened, for instance, the radiator thermostat in the room concerned reduces the heating power while the room is being ventilated, thereby saving both energy and money.