The lightweight Specialized Propero 4 Bike Helmet brings comfort, confidence, and high speeds to our ride with its durable full-wrap polycarbonate shell, optimized ventilation, and aerodynamic technologies. Using the DNA of the S-Works Prevail 3 and S-Works Evade 3 helmets, Specialized designed a helmet that balances speed and ventilation by utilizing Computational Fluid Dynamics (CFD) for an increase in airflow and cooling with the leading-edge aerodynamic efficiency of the front-end design. To increase protection, we adjust the FS3 Fit System and Occipital Base Adjustment for a personalized fit for our head shape, keeping the helmet secure and in place, while the use of Mips technology reduces rotational force to the head upon unwanted impacts.