evo.com | Castelli Ball Caps > The Castelli Difesa Thermal Cap ramps up the heat with full wicking capability and good ear coverage. Feel the warmth of the Thermoflex Core2 fabric and do away with that nasty brain freeze on your winter rides. One Size Fits Most Thermoflex Core2 Fabric Warmth with optimal wicking Wool Blend Ear Cover | Castelli Difesa Thermal Cap 2021 in Black | Wool