Ski Trab Casco Aero is a helmet with triple homologation, ideal mainly for mountaineering and ski touring, but also approved for cycling. You will have a single helmet to use in every situation that requires it! The outer shell is in polycarbonate with a matte finish, while the interior is in high-density polystyrene, super comfortable and protective. To increase comfort there are also comfortable microfiber padding. There is also a head circumference adjuster, quick and easy to use. Helmet sizes: S-M (head circumference 52 - 56 cm) L-XL (head circumference 58 - 62 cm) Ski Trab Aero ski-mountaineering helmet