The KN95 is an industry standard for respiratory equipment designed to filter out at least 95% of particles that are 0.3 microns or larger in size — the same measure used for the scarce N95 mask. Like the N95, the KN95 fits closely around the nose and mouth, creating a seal that decreases the risk of infection
KN95 masks are considered respiratory protective equipment that conform to GB2626-006 standards. They offer significant protection over standard surgical blue 3 ply masks and are approved by the CDC as acceptable replacements if N95 masks are unavailable. https://www.cdc.gov/coronavirus/2019-ncov/hcp/respirators-strategy/crisis-alternate-strategies.html
These masks are manufactured in an FDA certified factory and are approved to provide protection against harmful airborne matter. Link provided below: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfRL/rl.cfm?lid=652819&lpcd=KHA
These are individually wrapped masks sold as a single mask.