Cannondale's Quick Kids helmet offers big protection for little riders. Featuring In Fusion mold technology for lightweight durability, this kid-friendly helmet also boasts vent screens that let air flow in and keep bugs out, comfy straps with pinch guards, plus Cannondale's padded, Easy Fit micro-dial retention system for a perfect fit. The Quick Kids is a helmet kids love to wear! - X-Small/Small = 48-54cm - Small/Medium = 52-57cm