ULTRA BOOST ST SHOES - A LIGHT, LUXURIOUSLY CUSHIONED STABILITY SHOE FOR ANY PACE AND ANY DISTANCE. These men's running shoes are the ultimate experience in luxurious stability. Whether you're training or running a full marathon, their plush boost midsole keeps every step charged with energy. An adaptive adidas Primeknit upper and ergonomic heel give lightweight support exactly where it's needed, and a STRETCHWEB outsole provides a smooth, stable heel-to-toe transition. Weight : 12.2 ounces (size 9). 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. TORSION? SYSTEM for midfoot integrity; Ergonomic heel structure for added support. STRETCHWEB rubber outsole is lightweight and elastic, adapting to the ground for stability and working strategically to optimize the unique properties of boost from touchdown to push-off; Continental Rubber outsole for extraordinary grip in wet and dry. Runner type : stable; Use : everyday trainer; Stack height : 32 mm / 24 mm (8 mm differential).