Specialized Propero 4 Helmet AERODYNAMICS: With extensive testing in CFD and in Specialized's Win Tunnel, aerodynamics were at the forefront of the Propero 4 development. Specialized took the aerodynamic leading edge from the S-Works Evade 3 and pulled it directly into the Propero 4—which helped it to be four watts, or 15 seconds over 40km, faster than their S-Works Prevail 3. VENTILATION: Drawing inspiration from their world-renowned S-Works Prevail 3, Specialized's goal was not merely to replicate but to elevate. Ventilation became a focal point in their quest for a well-balanced, aerodynamic, and ventilated helmet. Specialized incorporated the rear-end design language of the S-Works Prevail 3 and introduced small 2mm offset micro-channels that create turbulence in the airflow throughout the helmet to help create a continuous, refreshing flow of air. ATTENTION TO DETAIL: Beyond just aerodynamics and ventilation, the Propero 4 represents meticulous attention to detail. Specialized went the extra mile by incorporating cutting-edge technologies from their S-Works level helmets, like MIPS technology for confidence, and a fit system designed to deliver all-day comfort. The Propero 4 doesn't just meet expectations; it redefines them. Mips Evolve Solution is a low-friction layer that allows a sliding motion of 10 to 15mm in all directions. Studies indicate that this reduces some of the rotational forces transmitted to the brain during angled impacts. Propero 4 earned the highest 5-Star Virginia Tech Helmet Rating from internationally renowned Virginia Polytechnic Institute and State University. FS3 Fit System & Occipital Base Adjustment optimizes comfort by personalising fit to individual head shape, and helmet angle can be adjusted for compatibility with glasses. Adjustable Tri-Fix web splitter combined with thin 10mm webbing for increased comfort. Dedicated sunglass storage maintains a secure fit and keeps eyewear out of the way when needed. Micro Channeling & large rear-end vents for increased ventilation. S-Works Evade 3 front-end design language for enhanced Aerodynamics. Precision, full-wrap polycarbonate shell for increased durability and premium finish.