Safety Zone has brought an economical NIOSH (National Institute for Occupational Safety and Health) approved dust mask to the market. They come packaged 20 masks per box, and 12 boxes per case. Take a look at our other dust face masks available, if these are not the particular masks you are looking for. To attach to your face, hold the mask in your hand and place your face into the mask. Then pull the top strap over and secure to the back of your head, and finally pull the bottom strap over and secure to the back of your head, near your neck. One size fits all. We also have a NIOSH approved particulate mask w/ exhalation valve available as well too.