The Michelin Airstop Tube is a .9mm thick butyl tube designed for increased puncture resistance..9mm thick butyl tube for increased puncture resistanceItem SpecificationsWeight120gValvePrestaISO Diameter622 / road / 29"ISO Width25,26,27,28,29,30,31,32mmLabeled Size700c x 25-32Valve LengthShort 32-40mmTube CompoundButylValve CoreFixedValve ShaftSmooth