Thin where it needs to be but warm all over. By combining a technical fleece neck warmer with the power of Thermax material on the head, the result is a lightweight technical piece that delivers comfort and warmth with the ability to fit seamlessly under hats or helmets. Thermax is a high performance hollow core polyester that provides maximum wicking while retaining heat, meaning you can stay warm and comfortable in almost any conditions. Recommended for: On-mountain cold weather adventures (skiing, snowboarding, hiking, fishing, etc) | Seirus Thick N' Thin Headliner in Black