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 Shawn Bass

You have "updated" replacement filters. What they actually did was make the new replacement parts no longer fit the old devices by changing the size a bit so now you have to force the back panel shut instead of just snapping it into place. Thought maybe it was installed wrong. No, I put the old filter back in place and the back panel closed easily as it should. I then replaced it again with a new filter, making sure the arrow was pointing in the right direction and inserting the filter as deep as possible. And again I had to forcefully close the panel. The plastic tab on the plate will most likely break after you've done this a few times. Yes, I am using the correct size (C pet filter which I have ordered from Revain several times in the past). It's most likely planned obsolescence by an unethical company hoping you'll buy a new air purifier. Sorry I will be replacing my air purifier by buying it from a competitor.