Works with Zipp butyl inner tubes with a removable core as well as other leading tubular tires and inner tubes that have removable cores. Available as a kit (3 extenders and 2 wrenches) or individually. - For use with removable valve core Presta tubes - Knurled end to keep pump from slipping - 3mm hex broach in the barrel to guarantee a perfect seal when tightened - Integrated air seal