This Flag helmet is certified for Skateboarding, Inline skating, Biking, and Snowboarding. This is a hard impact helmet with a Sweat aborbing lining that will keep your head dry. It is designed for knocking into hard curbs, and coming down unexpectedly on asphalt. Unlike the "soft" foam bike helmet, this rough sport helmet protects your head from injury. Besides, it has a special moldable inside to mold the shape of your head after just a few days of wearing. To figure out the right size to buy, measure around forehead using a tape measure or a string.