Urban Air Filters by Airinum offer superior replaceable filter protection—a five-layer patented system of breathable polypropylene, with an inside active carbon layer to reduce odors, and 2 electro-charged layers to filter micropollutants, bacteria, and allergens, for use up to 100 hours. Memory nose foam for minimal air leakage and no foggy glasses. Ergonomically designed for all face shapes. Easily replaceable.