These masks are designed with an anti-microbial, wicking-mesh lining and an exterior shell made of a water-repellant antimicrobial spandex blend that is UPF 50. Available in two sizes; the S/M is 5” in height and the L/XL is 6” in height. Fit is adjustable on the ear straps. Features small PSIA-AASI logos. These are not surgical- or medical-grade masks; they are recommended for personal hygiene. This item cannot be returned.