BLUEAIRClassic 500/600 Series Genuine Dual Protection Replacement Filter; fits Classic 580i, 680i, 501, 503, 505, 510, 550E, 555EB, 601, 605

Yes, they are pricey. Other, cheaper brands of replacement filters may claim to be compatible, but you will be compromising the performance of the unit and may even damage it.I'm not a shill for BlueAir, but we own 7 of their filters and they work great.It's important to understand BlueAIr units do *not* use HEPA filter media, but they *achieve* HEPA filter media performance using a unique combination of an ionization chamber where air is drawn into the unit (imparting a charge to particles in that air) and a filter media which builds up an opposite charge from the friction of air molecules passing through the media. The opposite charge attracts the charged particles in the air stream and binds the particles to the filter media, removing them from the air stream which then passes into the room.This means the unit *as a whole* removes just as many impurities as a HEPA filter, while providing a much higher clean air delivery rate (CADR) over a wider area than a HEPA filter, as HEPA media greatly restricts the airflow due to the high density of the media.Additionally, it is harder for the fan in the unit to push air through denser HEPA filter media, creating back pressure which causes excessive wear on the fan motor.All I can say is our BlueAir units are still going strong after over 20 years of continuous, daily use using authentic BlueAir replacement filters. We've also had some HEPA filter units which took longer to clean the air, only improved the air quality in a portion of a room, were much noisier and eventually became unusable after a few years due to fan motor bearing failure (which made them very noisy, even though they technically still functioned), or the lack of availability of replacement filters.

This is the 3rd time that I have ordered this set of three filters. They have worked very well in the air purifier, which requires three filters. This time Amazon sent only one filter, despite the product description of "three filters". Amazon replaced the incorrect item with, again, only one filter. So it is a very good item, but only if you can get a full set.

Quality of these replacement filters are second to none. Definitely buy the name brand filter it’s a mistake not to. Keeps smells down and room cleaner. They are low noise and perform better then the knock offs. Performance wise these are the ones you want.

This is a review of Amazon's inability to effectively sell a correctly package of the Blueair Classic 500/600 Series Genuine Dual Protection Filter. I had historically been purchasing elsewhere based the bad review experiences about incomplete orders; but in a regretful moment of trying to save a few dollars with subscribe and save I am sad to share I also experienced the same missing parts that so many other Reviewers who said Amazon was only shipping 1x of the filter pads even when the description clearly states: the 500/600 series air purifiers use 3 separate filters, this replacement pack contains a set of 3 filters. It boggles my mind that Amazon continues to make this mistake even after over 20 months of reviewers stating this. What's even more concerning to me would be how many buyers are unwittingly paying thrice the price for these filter pads.I reached out to Amazon and their standard offer for me was to return or replace. I opted to speak with customer service because I wanted to ask if a replacement would contain 3x or 1x pads. To their credit, Amazon couldn't answer my question and acknowledged it was their mistake. I asked couldn't they just mail me out 2 more pads and we call it fair and square. After the technician disappeared for a bit presumably discussing with a supervisor he returned and informed me Amazon will be promptly refunding my purchase and I could use, donate, or dispose of my one single pad. I'm glad to get a refund but still I encouraged Amazon to escalate this issue to a team to investigate why this item continues to be mispackaged. I got a standard line it would be escalated but I can't help still feeling skeptical.Why isn't Blueair taking a more vested interest in resolving this packaging issue with the largest retailer in the world? I reached out to Blueair though no answer yet. I ended up buying straight from Blueair which may be exactly what they want. But if I do get an answer I'll come back and update my review. In any case, take my word, and the word of so many other reviewers don't bother trying to buy this from Amazon until they address the packaging issue.By the way, for those of you interested in the product itself, the DualProtection pad is great and is a combination of the particle and the older carbon-based smokestop filter; Blueair's premium filter product. Its high quality, well-packaged and doesn't put off any odors at all. The pad fits perfectly and would be exactly what we needed if only it came as the pack of 3 as indicated.

The product is great... except that I need 3 filters to complete the order. I paid for 3 as stated in the description and only received 1 filter. Please send me the 2 additional filters ASAP.