THIS IS THE BEST FILTER I'VE EVER USED. I DON'T KNOW THE MERV RATING, BUT IT HAS BEEN MUCH BETTER THAN EVERY OTHER FILTER EVER. THE ONLY DOWNFALL IS HOW POORLY THIS FILTER IS CONSTRUCTED. GLUE ON EVERYTHING! TRY IT FOR 1 MONTH (IN THE WINTER). YOU'LL SEE EVIDENCE ON THE FILTER! THE BEST!! ANYBODY THAT TELLS YOU THIS DOESN'T WORK, MUST HAVE DONE SOMETHING WRONG!