DetailsDisc Valve Adapter & Patches:~ Zipp Disc Valve Adaptor has synthetic elastomer gasket with 2X the holding power and 5X wear resistance of traditional gasket materials. New, two stage seal design, improves sealing and stability on all presta valve stems. Adjustable compression, user can tighten the cap to increase holding power by 4X and compensate for wear. 15 degree stem angle reduces stress on the valve stem from pump hose. Comes with 5 patches.