great product and quick del

100% perfect in quality, in size and durability

This cardboard frame of this filter is MUCH sturdier than the filters I have purchased the past two years. So happy I found Filterbuy

the 20x21x1 Merv 11 fits my furnace much better than the typical 20x20x1. Most places do not carry the 20x21. Great job Filter Buy!

This Filterbuy 20x21x1 is actually 20x21, not 1/2 smaller each direction, which is the size needed for my Trane air handler.

Very happy with your service. Thank you.

Filtration of the filters are great, and support of the company goes beyond expectations.

Much better than the other brand you find that starts with an A.

My filter is a bit off the usual size, 20 X 21 X 1 and requires a custom build. This first one (of 3 ordered) barely fit it the slot. In fact it did not fit until I tried sending in the other end first.

I confirmed with the rep, that the 20 x 21 was actually 20 7/8 x 21 7/8. It was the former, not the latter. The fit was too snug. Although I was able to get it into the frame, I had to force it.Also, they had a yellow color, which made me wonder how old they were.