The filters came, I modified my filter box (the electronic filter stopped working) and the filter is working very well. That said, these are pretty thin, so I don't know how long it will go before needing replacement, but at this low cost, it can need replacement more often and still be a good deal.My one complaint is the INCESSANT badgering to sign up for automatic ordering. I'll probably keep ordering these, but I found the badgering so obnoxious that I'm considering looking elsewhere.
One of my filters had a gap at end where media was glued to cardboard frame. Had to break glue joint and reposition media and glue together with contact cement
I think you have a mistake in your files. I bought 21x21.5x2 MERV 13. I am using it without any problems. I feel that the air is cleaner than before because there is no dust on the goods. Please be careful not to supply the wrong filters when I make a reorder.