A trail-ready helmet with skate-style design and a smooth profile, the Giro Feature bike helmet offers extra coverage and high performance for long MTB days. In-mold construction bonds the helmet's outer shell to its EPS foam layer to provide a sturdier, more solid helmet. In-Form fit system features more surface area in the back to cradle the back of your head; adjusts in two ways (circumference and fore/aft tilt) to give you the best possible fit. 12 vents with internal channeling increase airflow so you stay cooler and more comfortable. Adjustable, moto-style visor is longer to offer better protection from the sun; easily tilts out of the way when you don't need it. Plush padding ensures comfort and fit while soaking up sweat. Goggle-compatible for muddy trail rides. Size small fits head circumferences 20-21.75 in. (51-55 cm). Size medium fits head circumferences 21.75-23.25 in. (55-59 cm). Size large fits head circumferences 23.25-24.75 in. (59-63 cm).