... type:2ply,3ply,4ply. -Size:17.5*9.5,14.5*9.5cm -Style:Ear-loop or Tie-on -Non- ... -Flu, with a filter encased in 3 layers of non-woven fabrics3.BFE95%, BFE99% filter paper and Normal filter paper4 ... Mask, with a filter encased in 3 layers of non-woven fabrics. It has high filtration efficiency and is ... Flu, with a filter encased in 3 layers of non-woven fabrics2, With elastic ear loops of straps and a ...