Abstract: A base module has a base connection surface with a projection formed around a first opening. A functional module has an engagement element arranged at a second opening having a recess with an edge forming a stop. A sealing socket runs around the second opening. A cap structure includes a frame running around the second opening, a plug-in receptacle connected to the frame and having a latching hook, and a soft component arranged on the frame facing the functional connection surface. The engagement element can be inserted into the plug-in receptacle with the soft component resting against the sealing socket and the latching hook engaged in the recess. A connecting device is provided between the modules. When the connecting device is open, the latching hook makes contact with the stop and the sealing socket is supported on the soft component with the connection surfaces spaced apart.

Abstract: A base module has a base connection surface with a projection formed around a first opening. A functional module has an engagement element arranged at a second opening having a recess with an edge forming a stop. A sealing socket runs around the second opening. A cap structure includes a frame running around the second opening, a plug-in receptacle connected to the frame and having a latching hook, and a soft component arranged on the frame facing the functional connection surface. The engagement element can be inserted into the plug-in receptacle with the soft component resting against the sealing socket and the latching hook engaged in the recess. A connecting device is provided between the modules. When the connecting device is open, the latching hook makes contact with the stop and the sealing socket is supported on the soft component with the connection surfaces spaced apart.