Valve stem extenders screw on to the existing Schrader valve stem on your roller ski wheels allowing for an easier connection with the air pump fitting. This means less torquing on your valve stem, prolonging the life of your inner tube!
These can be left screwed onto your roller ski tire, but confirm that once on, they do not interfere with the rotation of the tire and the roller ski forks--sometimes stems can be at an off angle. If this is the case, do not leave valve stem extender permanently on the valve stem.
Sold as a single item.