The PUMA ForeverRun Nitro2 uses nitrogen-injected NITROFOAM through the midsole to provide lightweight cushioning with extra spring. The RUNGUIDE SYSTSEM helps to control gently your stride through the most efficient gait while up top, an engineered mesh upper offers breathability and durability. PUMAGRIP rubber in the outsole provides excellent traction whatever the conditions, while also enhancing durability, so you get the most miles out your shoes.