The Scamp MIPS II is Giro's smallest helmet designed for young riders, but it still goes big with features and style. Taking design cues from adult helmets, this lightweight in-mold helmet features impact-dissipating EPS foam with a sturdy polycarbonate shell, plus 13 vents for efficient cooling power. The Mips® Evolve Core helps reduce rotational energy in certain impacts, and the Roc Loc® Junior fit system provides extra adjustability with a simple-to-use dial for several years of head protection for fast-growing rippers. Whether they're rolling along in a trailer or powering the pedals themselves, Scamp II is going to make kids want more bike time. Features: Adjustable youth bike helmet Roc Loc® Jr. Fit System for a custom and comfortable fit 13 vents and internal channeling for optimal comfort In-mold polycarbonate shell with EPS liner for maximum safety Evolve Core technology helps reduce rotational forces while enhancing fit and comfort Reflective rear decal XS: Complies with the US CPSC Safety Standard for Bicycle Helmets for Persons Age 1 and Older (Extended Head Coverage) S: Complies with the US CPSC Safety Standard for Bicycle Helmet for Persons Age 5 and Older Sizing: XS: 45 cm – 49 cm S: 49 cm – 53 cm