BELL Z20 MIPS JOY RIDE HELMETSharing all the DNA of the Z20, the women's specific Z20 Joy Ride is Bell's most sophisticated road helmet ever, representing several years spent researching fit, aerodynamics and impact protection. They combine Progressive Layering, a shell within a shell basically, utilizing an integrated MIPS slip plane, in order to achieve a helmet that reduces bulk, more closely conforms to your head, fits like a glove, and offers a sophisticated approach to energy management. The careful design of the dual shells allows Bell to maximize ventilation, and the fit is further enhanced by use of their height and width adjustable Float Fit Race retention system and unique Sweat Guide lining. Centuries to sprints, lung-searing mountain passes to fast pacelines, with the Z20 Joy Ride, there's nothing holding you back.FeaturesMIPS Equipped for better protection from impacts.Sweat Guide Padding directs sweat away from the eyes.Float Fit Race for the best fit.SizingHow to Measure: With a cloth measuring tape, find your heads circumference just above the ears.Helmet SizeSmallMediumLargeHead Circumference20"-22"52cm-56cm21.6"-23.2"55cm-59cm22.8"-24.4"58cm-62cm