Suitable wireless-window contact for energy-saving controller order no. 61 61 00. You can reduce the heating cost by the use of the window contact because a ventilation is automatically & quickly detected, as via the energy saving controller. The window contact sends a signal to the energy saving controller, after which it opens the window to close the radiator valve. The window contact is particularly recommended, if the heating element is not in the proximity of the window. Several energy-saving controllers can be attached