Panaracer has been crafting bicycle tires and tubes for more than 65 years. With the Panaracer line of tubes now available, we bring our same precision engineering to the most essential of cycling products; the inner tube. Available in all major sizes, valve lengths and styles and with a variety of core and sealing options.
There are two rows on the box. The top row is what we are used to seeing and is what your tire will be labeled as. The second row is the ISO size of the tube. Both contain the same information but are displayed differently. The red boxes show the diameter of the rim the tube can be used with. 18/25 on a tube indicate a range of tire widths with which the tube is compatible. When selecting a tube, you should look for the narrowest range that will fit. For example, If you had a 23mm wide tire, 18/23 would be a better choice than 23/25, though both will be better than a 28/32.