adidas ultraboost 21 grethr grethr grefou sustained grey • The soft nylon yarn

• The soft nylon yarn is woven in a unique construction that more efficiently dissipates heat from the body • Open back

A soft and flexible synthetic footbed offers all-day comfort

drawstring waistband

A classic low profile silhouette with our signature branding

Keep your look simple and comfortable with our luxurious Chelsea boots

adidas ultraboost 21 grethr grethr grefou sustained grey • The soft nylon yarnThe feel good running shoe in its 21st generation. Ultraboost 21 offers optimal cushioning alongside a socklike fit for a comfortable ride for both everyday and high performance use. Boost technology builds a response in energy to keep you going while maintaining the most modern style available. continental outsole for good grip and reliability on varied terrain.