Compass Fit ensures custom fit in seconds with the twist of a dial Integrated DVRT rotational energy management solution provides comfort & protection Engineered with lightweight, high impact-absorbing ZipMold+ technology Soft flip visor to shield sun from children&';s eyes Recommended for children ages 5-8 years old XS/S size for head circumference 48 - 51.5 cm S/M size for head circumference 51.5 - 54.5 cm Our recommended kid&';s helmet for eBike passengers