Mono mesh upper with toe drainage port Nitro foam provides superior responsiveness and cushioning in a lightweight package ProFoamLite: Extremely lightweight Ethylene vinyl acetate designed to cushion landing and propel each step OptiFit adaptive fit system designed to offer a secure lockdown and support during exercise Pumagrip ATR rubber compound outsole designed for traction on ice and mud and unstable surfaces Introducing Puma's First Hiking Specific Shoe: The Explore Nitro Mid. It's Designed For All Trails, From Flat And Gravelly To Steep And Rocky, With A Combination Of Nitro Foam And Profoamlite Through The Midsole Maximizing Comfort Over Any Terrain. Throw In A Pumagrip Atr Outsole And A Unique Collar Shape Complete With Integrated, Heel Supporting Lacing System And You Have Your Next Trail Companion. Get Ready To Tackle And Terrain, No Matter The Season.