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. The 3 layer construction together with a nose bridge adjuster & articulated nose & chin, limits repsiratory particle spread. This is the 5-pack in plain black colour. If you want something with a little bit more colour & patterns, we would highly recommend the 3-packs that is available in a range of different colours & patterns. 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. Airhole has been making facemasks for many years & know a thing or two how to create a comfortable & functional facemask. Multiple layers of fabric means less chance that respiratory particles can pass through the mask. Thicker, denser fabrics do a better job than thinner, loosely woven or knit fabrics. Due to the nature of the product this mask is excluded from our returns policy.