These are 3 layer masks.. that tie behind the ears. The outer layer is a tightly woven Taslon Nylon.. same that we use in the active wear vest.. The second layer is a cooling material, then a silk lining. Silk has proven to be a 90% protection ( University of Chicago)..Weighs 1 oz. Hand wash. Inside nose piece to form over nose. Helps prevent fogging. Here in the NW when its 100% humidity, if it fogs up.. I take a deeper breathe in.. and it clears. Good lung exercise.