1.Certified Kf94 Made In Korea - High Quality (mb) Filters - Fine Dust And Particle Blocking Face Mask - Kmoel Standard - Korea Osha Tested And Certified 2. 4-Layer Protection with high quality filter: Advanced electret filters using a quadruple filtration system filters out 94% 0.4m particles. 3. Our product uses Nano-Level Thread for easy breathing and better protection from fine dust. Comfortable 3D Structure ERGONOMIC Design with Anti-Fog Treatment around your nose line. 4. High Level Filter: It uses high level thread for easy breathing and better product from fine dust. 5. Certificate: FDA, CE, KFDA