The Ultra Boost 19 differs from the original adidas Ultra Boost, and the biggest differences can be seen in four key components - the optimised boost, the twist spring, the Primeknit 360 and the three-dimensional heel stabiliser. Optimised Boost outsole features 20% more foam in the midsole compared to the first generation Adidas Ultra Boost, this upgraded technology delivers even more energy recovery when running than previous UB models! The torsion spring is a lightweight design for better handling when the foot touches the surface of the ground and easy transition from heel to toe. Primeknit 360 resembles a second skin, combining pure comfort with lightness and breathability of the material. Last but not least is the three-dimensional heel-shaped stabilizer. The wrap-around design sways the heel, providing the perfect combination of flexibility and support.