Fwiw KN95 (Chinese standard) are available from Costco online for about $2.50 a piece. I assume Costco isn't selling fakes. They have ear loops so the fit isn't as tight as N95 masks and needs some fiddling.
KN94 is the Korean standard. They made their own because the need for a standard arose because of the dust that comes from China. Not sure what KN95 is.
Because multiple governments have found themselves with millions of dollars of fake/noncompliant masks, and last I checked, Costco doesn't have a mask testing facility.
