Completely reimagined, the Ultra Boost 19 builds on the success of its predecessor by reducing and refining its components. By optimizing the fusion of Boost pellets, designers managed to add 20% more Boost resulting in a softer and springer ride. To provide a better transition and add propulsion, the plastic torsion spring is now encapsulated within the midsole. Underfoot, the Continental Stretchweb outsole's new design features a larger contact area for 20% better traction on a variety of surfaces and weather conditions. Finished off with the worlds first 3D knitted upper and heel frame, the Ultra Boost 19 raises the bar for lightweight and supportive knit uppers.