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(R) Evolve Core helps reduce rotational energy in certain impacts, and the Roc Loc(R) 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(R) 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