The UltraBoost 20 '5th Anniversary Pack' celebrates a half-decade of the adidas UltraBoost. The black Primeknit upper is engineered to hug the foot in sock-like comfort, with Tailored Fiber Placement offering stitched-in reinforcement with contrasting purple threads. Silver three-stripes are complemented by an elastane heel in a grey and white gradient finish. The Boost midsole is similarly treated to gradient coloring, transitioning from purple to black to white.