InvisiClean Replacement Activated Carbon Prefilter - 4 Pack - Genuine Prefilter for InvisiClean Claro Air Purifier IC-4524[Amazon-developed Certification] Compact by Design

These filters work very well. I have three of the InvisiClean air purifiers in my house, and they all run constantly. These three machines are located in two bedrooms and in the den. I have cats, so the most visible sign that the filters work is the amount of cat fur they catch. I vacuum them clean every Sunday, as all three filters are visibly loaded after running constantly for a week. My subjective view is that--for my house--I should probably replace the filters monthly, because they seem to lose a bit of their power after that, but I stretch them out for three months. When I replace the filters, the HEPA filter underneath looks dirty, but that seems to be mostly just carbon from the pre-filters. I'm happy with the results I get from my InvisiClean products.

Expensive for a disposable item.

I had a little trouble figuring out how to make it stay in place but it definitely does the trick with keeping the air clean

I keep this air cleaner in my bedroom & it has done a great job with cleaning up my breathing air.

Nice product. Fits my air purifier perfectly. I would buy again.

only drawback is you can only get these from InvisiClean cut to fit. Makes them a bit pricy.

As expected

I like that fact that you can see the dust on it and you know it is working