Engineered for those unforgiving climbs and blistering heat, ARO3 is built with optimized ventilation to help keep you cool. Engineered for those unforgiving climbs and blistering heat, ARO3 is built with optimized ventilation to help keep you cool. TECHNOLOGY BOA® Provides an exact fit with a fully adjustable design. Mips® Technology Remain headstrong with an industry-leading, patented brain protection system that helps protect the head from multidirectional impact.