The Spiuk Rhombus helmet is suitable for both road and mountain riding. Its streamlined design and light weight provide an aerodynamic advantage to cyclists who need a top-end helmet at a reasonable price. It also includes an internal channel system joining front and back, improving ventilation effectiveness.CharacteristicsCycling helmetFor moderate-intensity road or mountain ridingInternal architecture for better cooling air flow W-Fit 82 rear fitting with adjustment wheel and three height positions , Includes removable visorTechnologiesThis product has earned EC certification, meeting the technical and quality criteria set out in the corresponding approval.Size Guide for HelmetsEach helmet specifies the appropriate measurements for each size in centimeters.size S-M: 52 -58 cmsize M-L: 58-62 cmTo establish the ideal size, measure your head's circumference, as indicated in the image.