Critical Cycles Classic Commuter Bike/Skate/Multi Sport cm-1 Helmet This is how to measure your head for a bike helmet:Measurethe circumference of your head. Put themeasuringtape about 1cm above your eyebrows and go all the way round your head in an even loop. US CPSC safety standard tested and approved.Classic skate design helmet with 11 vents to keep you cool and comfortable and 2 sets of interchangeable pads for a custom fit. Fully formed ABS surrounds high quality EPS foam to ensure safety on impact. Keep your head protected in this Critical Cycles helmet as you ride on your bikes, Skateboards, roller skates and scooters Pick from a variety of matte Colors to perfectly accent your bike and augment your personality and this helmet is recommended for riders who are age 14+.