Met strale helmetmets strale helmet utilises the venturi effect via an air channelling system that pulls in cool air while hot air exits through the back exhausting vents pushing it away from the rider the featherlight helmet is also unobtrusive whilst maintaining impressive aerodynamics as any top range all around helmet offering great value should be the strale is equipped with the safe t duo fit system which has micrometric adjustment 4 vertical adjustments and is ponytail compatible as