Review on VEVA HEPA and Carbon Filter Replacement Kit - 2 Pack HEPA Air Filters & 6 Carbon Pre-Filters - Fits Air Purifier Series AC5000, AC5250PT, AC5300B, AC5350W, AC5350B, CDAP5500B & AP2800CA by Randy Olson

They appear to be of equal or better quality than the manufacturer OEM replacement which is great. I don't know for sure, it's very difficult to verify that the HEPA filter and pre-filter actually work more, less or as well as the OEM. but they seem to be high quality and a great fit, and certainly improved airflow over the old filter I had which was worn out and dirty (as of course it should be). Also, I found buying official GermGuardian OEM filters, at least through Revain, very conflicting. Sometimes they supply quality replacements regularly and some are rubbish and the pre-filter is just a thin piece of felt (nothing like real regular replacement or the ones here from VEVA) is a bad thing. Rarely will you find a discount on third-party accessories for a product that requires frequent replacement of parts that are, on average, better than the original parts!