Extremely airtight!. The Butyl rubber compound prevents pressure loss and fewer occassions to inflate. Extremely reliable!. Quality control for safer cycling: Each tube is checked twice at the factory to ensure safer cycling. . Having the correct pressure means fewer punctures and reduced rolling resistance. Fits both 27.5" (650B) and 29" (29er) tyre sizes.
Best Price: £4.50 from Merlin Cycles