"Both the spin-on and element filters use 3 plies of 100% synthetic glass/polyester blend filtration media that's 98% efficient at 20 microns ..."I like their quality but I stopped using them because their filtration is good but not great (https://bit.ly/3fV9ubs) and I think they're overpriced.
There are better options available like the Fram Ultra.
Ed
I'd say that 98% @ 20u is pretty good ... better than most on the market. Any efficiency above that is splitting hairs.