From Over Under:

Our Long Sleeve 3-Season UltraLight Shirt is sure to find a place in your closet. Transitioning seamlessly from the dove field to your local watering hole, this is quite simply the best short sleeve shirt for warm weather. Crafted out of a durable yet breathable polyester/spandex blend and finished with a mesh venting system, we're confident this shirt will be the "must-bring" for any adventure to be had.