The Simms Gallatin Flannel LS Shirt is a durable Montana-style flannel crafted from 65% polyester, 34% rayon, and 2% spandex. Delivering UPF 50+ protection, water-resistance, quick-drying, wicking, and anti-odor properties, this 8.5 oz. shirt also has 2 fly box-compatible chest pockets for convenience. Perfect for all your fishing needs.