Homematic IP flush-mounted contact interface - 1-channel The Homematic IP flush-mounted contact interface - 1-channel enables the uncomplicated integration of a conventional switch, button or contact into the Homematic IP smart home system. In combination with Homematic IP actuators, existing lamps or roller shutters, for example, can be controlled intelligently and flexibly by radio via the Homematic IP system. Alternatively, the contact interface can also be used to activate or deactivate eco-mode in conjunction with Homematic IP climate-control products.