The Aura is one of the most recognizable Boa Closure System boots on the market. This double Boa system allows you to quickly and easily tighten both lower and upper zones independently with ease. Meaning you can fine tune your fit to exactly how you like it. Ride the uppers loose, or and the lowers tighter for better forward flex, or crank up the upper zone when you need more support. Features Flex Rating 5 (1 Most Flex / 10 Least Flex) V3 Footbed Trifit-X Liner Classiclite Outsole Double Boa System Glossary V3 FootbedV-Tech 3 density EVA foundation, Compression-molded multi-arch support shape, Slow-rebound EVA base for superior shock attenuation, Co-molded arch support cradle for all-day riding comfort, High-rebound EVA forefoot and heel impact relief pads, Airflow perforations, Anti-odor treated topsheet Trifit-X LinerDual-density, heat-moldable core, Asymmetrical X-Cage for nailed-in heel hold, Closed seam brushed fleece cuff, Soft foam interior cushioning layer, Comfort Flex toe box, Low-volume sole Classiclite OutsoleTwo-piece injected-molded UltraCush sole unit for a featherlight feel, Vans' special recipe rubber compound positioned in strategic high wear and traction areas for added grip and durability, Oversized inverted waffle tread pattern for increased traction and improved snow release Double Boa SystemFeatured on the mens and womens Aura boots, two reels control two specific zones of closure. The tongue dial controls the upper portion of the boot, while the side-mounted dial adjusts the lower portion of the boot, providing greater freedom of flex and articulation.