The Hermetic Plus Tubes are Recommended for Worry Free Cycling. Very Puncture Resistant in the Presence of Higher Butyl Amounts and Greater Wall Thickness. Retains Air Longer making this a Favourite Tube among Bicycle Rental Agencies. Size: 26" - 650x37-44 / 26x1.4-2.0" - 42mm Presta Valve Contents: 2 Continental Hermetic Plus Inner Tubes - New in Factory Packaging