MET Hooray Kids Helmet Dusted Green Size:S Features the Highest Grade of Size:Wide 80mm x 0.6mm X 5M Features the Highest Grade of Micrometer Thick TPUDeployed Across Seven Sealed Layers to Maximize Airtightness and DurabilityUncolored to Ensure the Highest Material Quality and Prevent Air Retention Issues Caused by Dye Related Surface ImperfectionsBase of Valve Shaft is Slightly Conical to Improve Fit to Wheel Rim and Reduce Unwanted MovementValve is Internally Threaded to Allow Use of Valve Extensions or Replacement Valve CoresLightweight and Durable Within a Small Packing SizeEasy to Repair chain line: 43 The new MET Hooray is safer internal engineered air channeling to improve ventilation and comfortReflective rear decal to enhance visibilityDesign compatible with child seatMET Safe T JR Fit System with 360° head belt to follow the growth of the childStraps with adjustable dividers for an individual fitAnti insect net embedded into the front ventsHand washable comfort padsCertifications: CE