I did buy this a few months ago because I like to have them on hand when needed. I buy this even though the guy who worked on my furnace and replaced the blower motor said not to use these filters. He said they were the cause of the blower motor going out, because they would have to work to hard and need replaced. But these filters, I believe, do what they are suppose to. I have dog's and these filters help me breath better when the air conditioner for summer or heater for winter.