Provides relief from all types of non toxic dusts and airborne particles. Sawdust, limestone, pollen dirt and so on. This product is not a respirator, but a nuisance control mask. Mask is light weight and comfortable to wear. Mask features a metal strap on the bridge of the nose to contour it to your face. Our customers call this the single strap mask even though todays mask has 2 straps. Packed and priced 50 pcs to a box.