$6.95 Per Tube & CO2! Our tubes are quality 700c 18-23 Butyl Road Bike tubes with 60 mm threaded Presta valves. Our threaded CO2 Cartridges are designed especially for inflating road bike tubes and contain 16 grams of CO2. The cartridges are conveniently packaged in quantities of six. Order just a few and pay shipping, or order a 6 Pack or 12 Pack for Free Shipping!