Just like the name, the Airhole Ergonomic mask is a low profile & form fitting that makes it perfect for smaller to mid size faces or for the wearer who would prefer a snug fit. This means that the Ergo Daily mask can be worn by younger children as well as adults. The 3 layer construction together with a nose bridge adjuster & articulated nose & chin, limits repsiratory particle spread. The Ergonomic facemask is sold as a 3-pack in various colours but is also available in a 5-pack in plain black colour. The Airhole daily masks have been designed based on Centres For Disease Control & Prevention, CDC guidelines. CDC is a national public health institute in the United States. Constructed with 3 layers of fabric that offer higher Air permeability & bacterial filtration efficiency. A facemask / facecovering with multiple layers of fabric means less chance that respiratory particles can pass through the mask. Thicker & denser fabrics on a facemask does a better job than thinner & loosley woven or knit ones.