66BHP skull cap in Thermo Stretch fabric, a helmet-friendly head cover with full ear coverage for riding and outdoor activity. The stretch fabric flexes with every movement, and the cap is very light for all-day wear. Full ear coverage protects against chilly winds and biting cold, keeping the ears warm so the wearer can stay out longer. It sits under a helmet for cycling, skiing or other outdoor activities, and suits slopes, mountain climbs and trails.