For Our Face Mask , it blocks droplets and the inside is heat treated, so lint does not occur when wearing it or after wearing it. Our products are produced with 100% made in Korea's non woven fabric and MB fabric. Quality certification and performance testing are fully certified by FDA, KFDA. Meet fast and accurate delivery dates and ensure full product warranty. KF94, Korea Food and Drug Administration Certification U.S. FDA Safety Certification I recommend it to you with the best quality All raw materials are reliable products made in Korea. We will do our best to fulfill all your conditions.