Durabasics HEPA Filter for Alen Air Purifier Filter Classic, BF35 & Breathe Smart Filter - Durabasics BF35 VOC Filter Fits Alen BreatheSmart Classic Air Purifier - Replacement for Allen Air Filters

It is still a bit expensive but works the same clearing the air in our home. It is worth the money to me.

Replacement filter for Alen Air Purifier- BF35 Breathe Smart

Lo tuve que regresar decía que me funcionaba para mi purificador de aire y la talla no era la correcta

Good price. Quality product.

I was getting a little tired of paying authentic Alen brand filter prices so decided to try a lower cost option. I have now gone through 3 of these in my BreatheSmart Classic. The fit is good and no issues inserting or removing them. The life of the filter as about as good as the original. I have not done any scientific study (nor will I...) about if this brand filters out exactly the same sized particles as the original but it does collect as much dust and dirt on them as the originals when they are spent and the filter light turns red. We have two cats and really have not seen much difference from using these vs the original higher end filters. This may be different if you have smoke or other more more challenging contaminants in your home, but we are satisfied with the performance of these and will continue to use them.