The masks seem definitely to be 4-ply and fairly thick, which I like—MUCH better than the usual 3-ply throw-aways. They arrived in a somewhat smashed box, but that’s probably a shipping issue. They are packaged 10 to a sealed packet. As soon as I opened a packet, tho, I could smell a chemical—hand sanitizer or perfume (a “known carcinogen”)—a major problem for me (or anyone else with chemical sensitivities). Overall, I like the masks—they seem good quality….if only they didn’t stink so much. I’m airing a packet outside now so I can use them at a future date—it takes several days to eliminate the smell. Not sure why everything from Amazon comes with an added stink! It’s not like it needs an extra benefit! LoL Without the stink, I would highly recommend these masks. I wear two with no breathing or speaking problems or use one in lieu of a filter and put a decorative/flowered cotton mask over it. Works great. Without the chemical, it would be 5 (or 10) stars!