I have a friend who introduced me to these. They are great for clubs and casinos where there is a lot of smoke and for toxic areas, like big cities, hospitals, or countryside that have high pollen count, etc.. These are far more superior to other brands of nostril filtration; and if your careful to apply to a clean dry surface of the nostril opening, you can actually remove them and reapply them a time or two. If they did not get soiled or wet, be sure to carefully remove them from the dry nostril and apply back to the original plastic sheeting where you pealed them off from.
They are great for clubs and casinos where there is a lot of smokemyhealthyair