Product Story The Lightweight Running Shoe That Will Do It All, No Matter The Terrain – The Fast-Trac Nitro 2 Has Dropped. It Delivers A Smooth Ride And Ground-Feel On Surfaces Including Loose Trails And Gravel, Thanks To A Full-Length Nitro Infused Top Layer Embedded In The Preformulate Midsole. Add To That The Durable Puma Grip-Atr Outsole And Integrated Eye Stays For A Snug Fit, Along With Details At The Toe That Help Drain Humidity And Protect From Debris – And You're Golden With This Groundbreaking Shoe Made For All Runners In All Four Seasons. Features & Benefits Nitro Infused: Enclosed Nitrogen-Injected Foam Designed To Provide Responsiveness And Cushioning In A Lightweight Package Preformulate: Extremely Lightweight Eva Designed To Cushion Your Landing And Propel Each Step Puma Grip Atr: Trail-Ready Performance Rubber Compound Designed For Traction On Ice, Mud, And Unstable Surfaces. Details Ripstop Mesh Upper Forefoot Drainage Ports And Debris Protectors Cushioning Level: Medium Puma Formstrip On The Lateral Side Heel-To-Toe Drop: 6Mm Shoe Pronation: Neutral.