... factory, cosmetology, restaurant, school, environment protection, public places and so on.3. The valid period of products is 5 years.Advantage ... have professional QC to control the product quality, the face mask comply with international quality standard such as CE, FDAWe have 8 ... elastic), PP mob cap(clip cap)Face mask: PP 1Ply-4Ply(earloop or tie-on)Picture: Face Mask Dust Mask Without Breathe Valve