High-performance face cover XL size with a 3-layer structure and 99% PFE (Particle Filtration Efficiency) for microparticles, passing the ASTM F 2299 test. Filter Performance: PFE microparticle filtration rate 99% Structure: 3-layer structure, filter adopted Testing Institution: Kaken Test Center Test Standard: ASTM F 2299 Size: XL Color: Navy New, unused. Please understand that this item has been stored at home.