Bests & Worsts Reviews from Amazon

I've tested a LOT of filters over the years for shop air filtration systems. THIS filter is the only one that gives very low flow resistance (lower than most MERV 8 filters) but, at the same time, it offers 94% filtration efficiency for particles > 0.5 microns. The secret is that this filter has about 2x as many pleats as every other filter I've tested so it has about the same filtration area as a 4" filter. That's how it gives the best of both worlds... low flow resistance like the cheap fiberglass filters and high filtration efficiency (MERV13) at the same time. I won't use any other filter from now on. Kudos to the 3M engineers who put this one together.