Made for great days on the bike and the daily commute alike, the Smith Signal helmet gives you the protection you need no matter where your wheels take you. MIPS® brain protection system helps reduce angled impact forces in the event of a crash, and an adjustable dial on back lets you fine-tune the fit for comfort. Strategic venting keeps the air flowing, your glasses fog-free, and your head cool. And whether you\'re grabbing a coffee or walking into the office, engineered eyewear channels make for convenient hands-free glasses storage. Key Features: 21 fixed vents for consistent airflow, Sweat-wicking liner insulates and fights odors, Lightweight, low-bulk single layer webbing, Weight (Size M, MIPS®): 11 oz / 3 g, Sizes: S - 51-55cm, M - 55-59cm, L - 59-62cm, XL - 61-65cm,.Protection Lightweight in-mold construction, MIPS® Brain Protection System reduces rotational forces caused by angled impacts to the head, CPSC and CE EN 178 certified, AS/NZS263 certified,. Fit / Integration Designed for ultimate integration with Smith performance goggles for maximum comfort, venting and storage convenience, AirEvac™ ventilation system integrates with Smith goggles for fog-free lenses,VaporFit™ dial adjustment system offers 27-degree fit adjustment with the turn of a dial .