Seirus Thermax Skull Liner is great for under helmets for an extra layer! Now get a thin, lightweight skull cap to fit under your helmet. Designed to wick away perspiration and yet keep you warm because this reversible liner is made of 100% Thermax polyester. You can wear it under your helmet, another hat for an extra layer or wear in alone. Fits great because it stretches. It's machine washable, made in the USA.
