I bought the filter for my new vacuum cleaner from Siemens because the filter that was there in the unit when buying, I found inadequate. Since it is the ventilation installed in this model above, you can smell immediately the dusty air that is ejected there. In contrast with this filter is better air out of the machine. You do not smell at least after dust. I find that reassuring. For allergic people it is a pleasant sensation. A reasonable filter should normally be there in the same device but with extras can be known to be making more money. There are certainly better filters but I find this quite well. So who does not want to suffocate in their own dust, can feel free to indulge such a part.
