Marmot Men's San Onofre Flannel Long Sleeve Tee 52% Cotton, 48% Coolmax Flannel 3.8 oz/yd Imported Quick-Drying and Wicking Soft, Comfortable, Light-Weight Performance Woven Fabric with Twill Texture Coolmax for Moisture Management Ultraviolet Protection Factor (UPF) 30 Durable Flat Felled Seams with Contrast Interior Stitch