Let me start by saying these Y6604 MERV16 filters are a solid choice if you're looking to save some cash compared to the OEM Lennox filters. I've been using them in my PureAir system for about 3 months now, and here's the real deal.

The good stuff first: The air quality improvement is noticeable! My allergy-prone family members have definitely breathed easier since installation. The carbon layer seems effective at reducing odors (goodbye, lingering cooking smells). Installation was a breeze - they slid right into my unit just like the expensive OEM filters.

Now the not-so-great: As other reviewers noted, these aren't perfect clones. The dimensions are slightly off (about 1/4" shorter than my original Lennox filter), though they still seal properly in my system. The packaging could definitely be sturdier - my first set arrived with a dented corner from shipping.

Here's what surprised me: Despite being 'knockoffs,' they seem well-constructed. The pleats are tight and even, and there's a decent amount of activated carbon. However, I did spot a minor typo in the printing (always makes you wonder about QA).

Pro tip: Buy these when you don't need them immediately. That way if you get a damaged shipment (which seems common based on reviews), you have time for replacements before your current filter expires.

Final verdict? For the price difference (about 1/3 of OEM filters), I can live with the minor imperfections. They're performing well so far, but I'll update if they don't last the full year as claimed.