The Seirus Thermax Headliner Balaclava puts a warm soft barrier between kids and their cold hard helmets Thermax-« fabric provides warmth without adding head squeezing bulk and the full coverage design spreads the warmth all the way down to their necks Thermax-« fabric is ultra thin warm and wicks moisture away from skin Flat lock seams offer a more comfortable low profile fit Four way stretch makes the liner easy to get on and off