Extension element for telephone substation for door intercommunication system of e.g. building, has fastening device directly attaching front-side functional surface at cuboid telephone housing of telephone substation

摘要

The element (10) has a fastening device directly attaching a front-side functional surface (16) at a cuboid telephone housing of a telephone substation, where the functional surface is equipped with additional devices. A clock, a slip holder, a hook for keys, a storage location for small articles, a pin wall portion and/or other additional devices are provided at the functional surface. The fastening device is connected with a frame part (20) partially embracing an external periphery of the housing. Detents are partially attached on clamping tabs (28a-28d). The frame part is formed as a circulation frame and a plug-on frame.