Filterbuy 21x21x1 Air Filter MERV 11 Allergy Defense, Pleated HVAC AC Furnace Filter Replacement, 12-Pack

My air handler requires a filter that is 21" x 21", but to find that size I would have to pay extra for a "non-standard" size, IF they were available. The website where I purchased my previous filters considered 21" x 21" filters to be a custom size, and they were going to cost me 50% more than what I paid for the 21" x 20" filters that I ended up buying. Enter Filterbuy to the rescue that has legitimate 21" x 21" filters for no extra cost!I haven't actually used any of these filters yet as I still have two filters left from the previous purchase from a website that will remain unnamed. Although I did open the package just to see how they fit. They fit like an air filter should fit, nice and snug with just enough clearance to be able to grab the corners and remove it.The frame is much stiffer than the filters I am currently using, so they don't have the cross flex or what I'll call droop in them like the current filters do. I was able to slide the Filterbuy filter in the channel without having to reach under and push the back of the filter up so it would install correctly. My physical limitations makes it impossible for me to install the other filters without using something long enough to reach under the air handler and then push up on the filter to get the back of it to slide in the rear channel.

Very difficult to find anywhere. Glad to see Filterbuy carries this size. Very sturdy and looks great. I feel safer using this filter and I think its doing a fantastic job. Great price too.