The BugsAway Breez'r Long Sleeve Shirt features Insect Shield technology and Flow Thru Ventilation to keep you cool and protected. The ripstop nylon is lightweight, wicking and quick drying to keep you dry and comfortable anywhere you roam. 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.