Primegreen: This product has been made with Primegreen: a series of high-performance recycled materials. BOOST: BOOST technology combines superb cushioning and energy return with every step and jump, fueling the athlete with endless energy. HEAT.RDY: KEEP COOL. Our cooling technologies and materials keep your feet feeling cool even in the biggest heat. Hot weather won't slow you down in these breathable running shoes. Vents in the midsole give your feet 360 degrees of cooling airflow on sizzling sidewalks. Boost cushioning energises your stride and offers feel-it-to-believe-it comfort. This product is made with Primegreen, a series of high-performance recycled materials.