Columbia's Insect Blocker Plaid Shirt features the outdoorsman's trifecta of performance: Insect Blocker technology wards off bugs, UPF 30 shields you from harsh UV rays, and Omni Wick moisture management keeps you cool and dry during dynamic activity. Polyester and nylon fabric with Insect Blocker. Insect Blocker technology uses naturally occurring chemicals to ward off biting insects mosquitoes, ticks, flies, and other biting insects. Omni Wick technology actively breathes and pulls sweat away from your body to keep you dry and cool. Omni Shade UPF 30 provides premium protection from the sun. Pocket with hook and loop closure. Mesh pocket bags. Roll up sleeves with tab holders. Sun protection collar. Vented to help keep you cool. Modern Classic Fit: Universal, easy fit for comfortable range of motion.