So far, so good
I cut a hole in my A/C plenum the exact size of this air filter.  The flanged lip holds it in place for this specific application, but it likely won't work if you are trying to replace an ordinary 20x20 square filter.  Order one without the lip for that applicaion.  Time will tell if it can go for 6 months to one year without needing to be changed.
Rating: 5 stars