CBS News - Where to find an N95 or high-filtration mask for Biden's 100-day challenge
KF94s from South Korea
KF94 masks, which meet standards set by the South Korean government, are generally seen as more consistent in quality than the KN95's from China, but still are not fully approved for use in health care settings in the U.S.
Korean cosmetics company Be Healthy sells KF94 masks imported from South Korea from a variety of different manufacturers. All of the products sold by the online company must meet South Korean standards, and some are also approved for use in Europe.
A study from the National Center for Biotechnology Information, comparing the effectiveness of surgical N95 and KF94 masks, found both types of masks to be equally effective.