Bill & Candy Cycling MTB Road Bicycle Helmet 18 Holes Riding Equipment Male And Female Models -Blue&pound;&uml;Head Circumference 56-62cm and the Head-width Below 17.5cm.please Check the Size Before Buying&pound;&copy; Use Special technical material, EPS increases impact resistance of composite materials Ultra-light, wind tunnel, duct design, effectively reduce wind resistance. High-quality foam layer, the adjustment within the twist, you can adjust the size of head circumference. Suitable for people with head circumference 56-62cm and the head-width below 17.5cm. 18 flow vents to keep you cool with snap on/off visor for sun protection