The Lowline II Lightweight Core Stretch Sweater is an overhead midlayer crafted from recycled polyester/elastane midweight fabric. It's warm, light, stretchy, and quick-drying. Featuring a half-zip fastening for adjustable airflow, it's perfect for outdoor activities like skiing, hiking, biking, and walking. This product uses 97% Polyester and 3% Elastane and recycled 15 plastic bottles.