When my wife and I bought our first house, we had to order our air filters. The HVAC system worked really well at cooling and heating our home. The Biggest problem was with the air filters. Our HVAC system required special sized air filters, and they were very difficult to find in the hardware store. We decided to order a large box of these special air filters from an online website. They were almost half the cost of our hardware store, so we ordered two dozen the first time. The shipping took almost ten days, but they arrived on the day promised. We pulled the air filters from the box, and they were exactly what we had ordered. Since it wasn’t time to change the air filters yet, I put the box in the basement. A few weeks later, e walked down to the basement to fetch the air filters. I pulled on e out to place in the HVAC system. As soon as I removed the air filter from the box completely, I could tell that the size was not the same as our other air filters. The entire air filter was about two inches smaller than the other. I carefully reviewed the sizes that were printed on the air filter. The new air filter was easily a full inch smaller than the old air filter.They had been inaccurately sized or labeled, but they were not the air filters that would fit my system. We called the manufacturer, who wasn’t very helpful at solving our problem. We ended up having to buy an expensive air filter from the hardware store, and we returned those cheaper air filters for a refund.