Our best-selling ¾-sleeve silhouette with Mosquito Protection Technology™ - tight weave fabric stops mosquitoes without toxic chemicals. Inspired by Nor Cal wildflowers and dawn hues. This 100% recycled polyester lightweight adventure shirt is designed to keep you cool and comfortable on the trail while protecting you from the sun and mosquitoes. fabric featuring new Northern California-inspired colors and prints. This 100% recycled polyester lightweight adventure shirt is designed to keep you cool and comfortable on the trail while protecting you from the sun and mosquitoes.