First Defense Nasal Screens are the first ever non inserted, self-adhering nasal filter. FDNS are designed to help filter and reduce the amount of contaminants that everyone inhales in all types of environments. First Defense Nasal Screens can be worn for up to 24 hours and are self-clearing so they will not clog and seal 100% of the nasal passage. FDNS allow one to wear glasses without fogging up and also allow someone to eat and communicate without the need for removal. They can be worn in extremely hot and cold environments without losing their extra strength moisture resistant and repelling hypo allergenic adhesive, which has also been tested and designed to be able to be worn daily without causing irritation to the skin. First Defense Nasal Screens are made in Monticello, Indiana.