ENVE knows a good thing when they see it. The folks at Silca have developed an amazing valve extender, and ENVE brings it in house with ENVE embossing on the gasket. The ENVE Silca Valve Extensions are things of beauty. They are precisely machined, have a gasket that seals in air at the base of the valve, another gasket where the core fits, and the threads are treated with a film sealant to eliminate any air leakage at the threads. There’s also a gasket on the outer wall to eliminate any clicking of the extension against the rim.