Whether you're in a buggy town or hanging out in camp, the ExOfficio's BugsAway Marigold, featuring Insect Shield technology, is the perfect shirt to keep you looking good and protected at the same time. 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. The comfortable cotton blend breathes and dries quickly for easy care, and ventilation keeps you cool on hot days. Insect Shield repellent lasts through 70 washings. Do not dry clean.