ASTM Level-3 (We also Have Level-2, Level-4) Product Description ASTM Level 3 - most premium Surgical mask, with BFE>99%, PFE>99% at 0.1 micron. Conforms and tested by USA Nelson Lab, meeting ASTM F2100 Level 3 and EN 14683 Type IIR requirements. Conform and pass Bioburden Test. Product origin : Malaysia Key Specifications/Special Features : Packing: 40pcs per box, 20boxes per carton Minimum Order Size and Packaging details : 10,000 Boxes