Michelin A1 AirStop 700 18/25c Presta Tube 40mmMichelin A-1 Airstop tubes are made from a high quality butyl rubber. AirstopĀ® Butyl tubes answer the needs of everyday cyclists for economical, high quality inner tubes. In each size, Airstop Butyl tubes offer excellent puncture resistance and the consistently high quality for which Michelin is famous. Their production process ensures consistent wall thickness for maximum air retention without wasted weight.086699103574