Fantastic product! I changed the filter behind the bag, and the performance increased noticeably. The best filter fits where it should, as indicated by the dimensions (the elongated one on the motor). Also, since it is cut to your measurements, there was an extra piece left for inside-behind the bag, and two pieces for outside, on the motor. Now I can change it more often than before (1 filter per 5 bags). VFM for €1.

I used it for an old Philips vacuum cleaner. With a little trimming, it fit quite well and seems to do its job.