Comments about Whirlpool Carbon Pre-Filter For AP35030, AP51030 and AP45030 (4 Pack) - 8171434:

The Whispure 510 does a great job of cleaning the air, even with smokers and pets in the house. I use it in the living room, and with my small house it makes a noticeable difference throughout the house. It's a bit bulky for such a small space, but is so quiet you have to look at the lights to see whether it's on if anything else in the house is making noise. Since it provides lights as visual cues as to the condition of the filters, it's easy to order these high quality inexpensive prefilters before they're needed, as well as to know just when the change the filter.

I love the fact that this store has such good filters so inexpensively to improve the quality and extend the life of my expensive air purifier.