Featuring Acclimate Dry fabric, the Double Base Layer collection contains microfibers that are cuddly soft to keep you toasty and dry during any outdoor cold weather activity. Mid-Weight with flat seam construction for ultimate comfort. 100% Acclimate Dry Polyester. Moisture Wicking, Breathable, Quick Drying. Anti-Microbial/anti-odor protection. Relaxed Fit that feels like cotton.