Zipp Tangente Aluminum Knurled Valve Extender - 98mm 1080 1 Piece Removable Presta Valve BLKZipp Tangente Aluminum Knurled Valve Extender 98mm for 1080 1 Piece for Removable Presta Valve Black. Zipp valve extenders for use with removable presta value tubes. For use with removable valve core presta tubes Works with Zipp butyl inner tubes with a removable core as well as other leading tubular tires and inner tubes that have removable cores Knurled end to keep pump from slipping 3mm hex broach in the barrel to guarantee a perfect seal when