Zipp Tangente Butyl Tube - 700 x 20-28mm 37mm Aluminum Presta ValveZipp Tangente Butyl Tube 700 x 20 28mm 37mm Aluminum Presta Valve. The Zipp Tangente butyl tubes are designed to meet the needs of a new era of road riding that includes adventures aboard wider tires. The tubes 0. 60mm thickness is optimized for durability. 37mm valve stem length Lightweight aluminum valve body with removable Presta valve core For use with Zipp Tangente Aluminum Knurled Valve Extender 0. 60mm thick to optimize durability When