The Soomlab Nano Fiber Mask is constructed using 4 separate layers of protection including a layer of nano fiber filtration capable of blocking particles as small as .1 micron which covers the entire surface of the mask face. Its efficiency rating is similar to that of an N95 respirator but the mask itself is far more comfortable. This mask may be used up to ten times and can be cleaned after use with 70% alcohol. Soomlab Nano Fiber Masks are slightly larger than the Air Queen masks for people with longer/larger faces and come in either black or white. We recommend rather than placing the elastic straps around the ears that they be connected at the back of the head using a mask clip (included free in each order). Proper fitting of a face mask to eliminate air gaps is as important for a mask's effectiveness the efficiency of the filtration material. This mask offers comfort, adaptability, and highly efficient filtration to most men and women with slightly larger faces/heads.