Insect shield technology protects you from insect bites and potentially dangerous insect-born diseases. Permethrin, a man-made version of its natural counterpart found in chrysanthemum plants, is tightly woven within the fabric to create an instant repellent. The fabric also protects from the sun's harmful UV rays with a UPF rating of 30. Underarm and back yoke ventilation provides air flow to keep you cool. Quick-drying and moisture-wicking 6-oz 65/35 polyester/cotton blend. Repellent is effective for up to 70 washings.