Retrospec Traverse H2 2-in-1 Convertible Helmet with 10 Vents 2-in-1 ultimate lightweight sports helmet, shred the slopes and ride the roads with two sets of inner pads and removable ear flaps! Easily personalize the fit to your head with the adjustable dial on the back of the helmet for a safer fit, Safety certified: CE EN 1077:2007 (Ski Helmets); CPSC 16 CFR, Part 1203 (Bicycle Helmets) Equipped with fleece snow cap and earmuffs to keep you warm, dry and protected and 14 vents to regulate your body temperature SIZE: S/M (54-58 cm) Converts into a bike/skate helmet by swapping out the fleece cap and earmuffs for the included traditional helmet foam padding