The cotton-blend BugsAway Chas'r, which is Insect Shield® Repellent Apparel from ExOfficio, offers bug and sun protection simultaneously with a UPF 30+ rating. Permethrin, the active ingredient in Insect Shield, is invisible, odorless, and so tightly bonded to the fabric fibers that it retains effective repellency through the life of the garment. It repels mosquitoes (including those carrying West Nile virus and malaria), ticks, ants, flies, chiggers and midges (no-see-ums). Insect Shield repellent lasts 70 washings. Do not dry clean.