FFP2 Masks are a European standard of design specification that is just below the NIOSH N95 standard used in the USA. KN95 is a design specification similar to the FFP2 used in Asia. These standards have now been recognized by the CDC and FDA for use in medical situations where N95 masks are not available.
Filtration to 0.3 microns and ≥94% effectiveness.
Read the 3M guide to safety masks and respirators. (These are NOT manufactured by 3M.)