A Mips® Safety System adds advanced impact protection, and there's a dedicated space for the Smith Transit Light (sold separately), which offers increased visibility any time of day. A good fit is the foundation of helmet safety, so it's available in two sizes and includes a dial-adjustable system to fine-tune fit and comfort.ProtectionMips® Safety System reduces rotational forces caused by angled impacts to the headLightweight in-mold construction fuses the exterior shell and EPS foam for a one-piece design that's lightweight and durableComplies with U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older as well as CE EN 1078 and AS/NZS2063Fit / IntegrationTwo sizes available: Youth X-Small (48-52cm, age range: 4-8); Youth Small (51-55cm, age range: 8-12)Adjustable dial fit system for a customized fitAirEvacventilation system integrates with Smith eyewear for fog-free lensesFeatures16 fixed vents for consistent airflowRemovable and rechargeable Transit Light compa