there is too much cardboard covering the filter element. I had to cut away all the cardboard on the air entry side and most of it on the air exit side; I left an X of cardboard for support on the air exit side.I use 10 x 10 x1 filters and having so much cardboard on such a small filter is unnecessary. Once I cut away the cardboard the air flow was much better and quieter.
Havent use them yet. But the shipping was immediate and packages really well. Im due to change my filter in 30 more days. Ill let you know how it works