Continental Light 700c Tubes The Continental 700c lightweight tubes are seamless and mold cured butyl rubber. The valve cores on the presta cores are removable and the valves are available in 36, 48, 60 and 80mm sizes to fit your specific rim profile. Features Removable Presta Cores Butyl Rubber36, 48, 60 and 80mm valves | Continental | 700C Light Presta Valve Tube 700 X 18-25, 60Mm Presta Valve, 80G | Rubber