Castelli WS Skully, For extreme cold conditions, the Windstopper X-Lite plus band covers the front of the cap and the top of the ears, while the bottom of the ears are covered in Warmer fabric so your hearing is not impaired. Coupled with this there is a long Warmer tail to keep the back of your neck cosy.Windstopper X-Light plus on front for wind protectionWarmer fleece fabric feels soft, wicks moisture, and is so comfortable under your helmetCut long at the back for perfect closure with jacketDesigned to fit under a helmet and cover the earsUni Size one size fits allFabric - 95% Polyester 5% Elastolefin (Olefin)