
According to the U.S. 3M company, maker of the N95 medical masks, also NIOSH, the Federal government regulatory agency over safety & hazardous materials, & the CDC, the KN95 mask is the N95 equivalent.
I get mine from this eBay seller who has a super high feedback rating and advertise that their KN95 masks are 5 layers. (Be careful of cheap knock-offs.) I've cut several open, so they are indeed 5 layers.

The ear straps are just a bit loose on me, so I tie a tiny knot in each one. But, that's perfect, as then the masks are adjustable. They also have a stitched in, bendable nose clip, so it won't fall off.
From this seller, they come sold in 10 packs, 20 packs and 50 packs. They are individually sealed in plastic bags, two to a bag, which can easily fit in your jeans back pocket. So you can easily swap one out for a clean new one if you feel it getting sweaty. Or you want a new one after eating.
Seller's page:
https://www.ebay.com/sch/m.html?_odkw=&_ssn=jp-genuine&item=154026055696&_osacat=0
I wore them last summer when it was so hot & humid outside. While they were a little thick, the fact that they were 5 layers actually helped absorb the little bit of sweat that collected at the bridge of my nose & top of my cheeks.