IIRC KF94 were designed as an easier to make general population mask in event of a pandemic (after SARS etc). It wasn’t meant to match N95 (or Korea’s equivale

IIRC KF94 were designed as an easier to make general population mask in event of a pandemic (after SARS etc). It wasn’t meant to match N95 (or Korea’s equivalent), but to get close. Ideally the US would have an equivalent, or have encouraged manufacture of one long ago, but we all know how that went.