Freedom Tube 29 X 1.9/2.125 Thorn Resistant 48mm Presta

Designed to be thicker on the road side and a little thinner on the rim side to keep the rolling weight lower than a standard thorn resistant tube.
Bicycle tube. To choose the correct tube size, find the size of your tyre and select the tube size to suit. Don't forget to check the valve type and if applicable, the valve length.