ultra boost - Step into these neutral women's running shoes and you will rethink everything you know about what fast and comfortable feel like. They're built with boost for incredible energy-returning cushioning beneath your feet. With a breathable adidas Primeknit upper for a flexible and supportive fit and a STRETCHWEB outsole for a smooth, neutral transition. A light, luxuriously cushioned running shoe for any pace and any distance. Weight : 283 g (size UK 5.5) adidas Primeknit is carefully engineered to naturally expand with your foot while you run to give you a more comfortable fit and help reduce irritation. boost 's energy-returning properties keep every step charged with an endless supply of light, fast energy. STRETCHWEB rubber outsole is lightweight and elastic, adapting to the ground for stability and working strategically to optimise the unique properties of boost from touchdown to push-off. TORSION? SYSTEM for midfoot integrity; Moulded 3-Stripes and heel counter for support and optimum heel hug.