why are they called 12 x 24?
Your review: Which would probably make them last longer, yeah, and save even more money. But, we don't need the dust all over, so I used a 1 inch strip of foam board to make the opening smaller. So far so good, but long term, I'll need a better solution
Pros: Very substantial filter, our first MERV higher than 4. Air flow-through seems good for our system. Global Ind. service is top notch, fast. Best price that I was able to find. They arrived today; after a month of use I can rate them again
Cons: I am the dope who did not read that the actual dimensions are almost an inch less on each side than listed. So I have a 1/4 inch gap along the sides of the filter.