This invention relates to an apparatus for vertically closing an opening, the apparatus comprising a fixed element attached to a surface and placed above an opening such as a window, doorway, or the like. The apparatus further comprising a roller connected to said fixed element, a shielding element attached to the roller, the shielding element being adapted to be wound on and unwound from the roller. The apparatus further comprising a number of sensor arrangements and a condition monitoring device configured to receive data from at least one of the number of sensor arrangements and to directly or indirectly compare the data with reference data such that a service need and/or a safety issue can be identified.