A lightweight performance layer that looks and feels good? Yes, please. The Women's Aella Long-Sleeve Shirt features AirExchange technology, which allows more air to pass through this long-sleeve shirt and keeps you cool, plus built-in UPF 20 sun protection. Flat-felled seams reduce abrasions and skin irritation, while forward-set shoulder seams increase comfort when you're traveling with a backpack. The button-down style adds stylish appeal during off days in town.