First Defense Nasal Screens are the only non-invasive nasal screen on the market. Reduce your respiratory exposure to viruses, bacteria, germs, chemicals and pollution. You can even prevent allergies. Each year there are millions of deaths due inhaled particles with viruses, bacteria or pollution that cause serious illness or even death. Reduce your exposure to these contaminants. Our Nasal Screens are able to filter 99% of particles size 10 um and above. And, 92% of particles size 2 um. This means you are dramatically reducing your exposure to contaminants you breathe in. Each individually sealed package includes 7 sets. Each set will last up to 24 hours of use. The Nasal Screens are as effective as a mask but so comfortable and discreet you can wear them anywhere. Peel and stick, don’t get sick.