When designing the Smith Convoy, we set out to create a mountain bike helmet that felt like it was tailor-made for your head. Turn the dial in back, and the VaporFit(TM) system adjusts like a halo around the skull. When it comes to comfort and protection, the helmet ticks all the boxes. It has a MIPSA(R) liner system and all the ventilation you&';ll need through the hottest days on the trail. In addition to easy integration with performance eyewear, it also features outside channels that store your shades when dusk sets in. Product Details Protection Lightweight in-mold construction MIPSA(R) Brain Protection System reduces rotational forces caused by angled impacts to the head CPSC and CE EN 1078 certified AS/NZS2063 certified Fit / Integration Designed for ultimate integration with Smith performance eyewear and goggles for maximum comfort, venting and storage convenience AirEvac(TM) ventilation system integrates with Smith eyewear for fog-free lenses VaporFit(TM) dial adjustment system offers 270-degree fit adjustment with the turn of a dial Features 20 fixed vents for consistent airflow Integrated visor Performance comfort lining Lightweight, low-bulk single-layer webbing Weight (Size M, MIPSA(R)): 11 oz / 300 g