I love these filters! I started using them at the very beginning of the Covid outbreak the Merv 15 I believe and nobody in my household has tested positive yet!
Okay, the price is right, however you get what you pay for. The cardboard framework is thin and flimsy and not a full 4 inches thick. They claim MERV 13, but the medium is not thick and fuzzy like Honeywell. Next time I'll spend the money and get Honeywell or similar.
You do what one expects. That is becoming increasingly unusual in this country of "alternate truths" and "fake news" and where people can't be man enough to admit they have lost.