Review on 🌬️ Germ Guardian FLT5250PT True HEPA Genuine Air Purifier Replacement Filter C for Pet Pure Treatment - Compatible with GermGuardian AC5250PT, AC5000E, AC5300B, AC5350W, AC5350B, CDAP5500, and More by John Baker

Germguardian have updated these filters, most likely to prevent people from using carbon substitutes from cheaper, better companies like Veva. They made the filters a bit thicker made. hence other activated carbon filters will not fit properly. The problem is that YOUR upgraded filter is now TOO THICK for the rear grille to close properly. And no, my AC5359W 28" air cleaner is not the problem. I have 3 of these and they all don't fit properly. Also, this filter is designed for this machine. A similar filter for my 22 inch 4000 series machine fits perfectly. So it's either fake or the improved Germguardian filter for their 28 inch machine is defective.