Specialized Propero 4 Helmet Introducing the new Specialized Propero 4 Helmet. It combines the aerodynamic perks of the S-Works Evade 3 with the ventilation of the S-Works Prevail 3. It maintains the comfort and assurance that Specialized helmets are renowned for, boasting the top-tier 5-Star Virginia Tech helmet safety rating. Propero 4 Highlights The Specialized Propero 4 goes beyond expectations. It features cutting edge MIPS technology and incorporates a fit syetem built for all day comfort. Every aspect of the Propero 4 is designed with Specialized's formula for speed: Aerodynamics + Ventilation + Lightweight = Fast. Aerodynamics are a key focus in the Propero 4 design, it is 4 watts or 15 seconds faster over 40km when compared with the S-Works Prevail 3. Ventilation is another key aspect in the design of the Specialized Propero 4 with it being carefully curated to provide a continuous refreshing flow of air.