This khaki 30A sun shield hat is part of Stetson’s NO FLY ZONE™ collection. What does that mean? Stetson’s NO FLY ZONE™ fabric incorporates odorless and invisible insect repellent technology, including a permethrin-permeated layer designed to drive off mosquitoes, ticks, ants, chiggers, flies and midges as soon as they land on it. These NO FLY ZONE™ hats are EPA registered and the permethrin fabric is recommended by both the CDC and WHO, making them environmentally friendly. The hat features a mesh insert with adjustable sizing toggle.