Crafted from a comfortable cotton blend, the BugsAway Chas'r Tee offers bug and sun protection simultaneously. The Chas'r is quick drying, odor resistant and moisture wicking to keep you cool and dry. Permethrin, the active ingredient in Insect Shield, is invisible, odorless, and tightly bonded to the fabric fibers, and lasts the expected lifetime of the garment (70 washes). 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.