The N45 Mid GTX is built for serious durability, ready to take on mile after mile-and it can be rebuilt to take on even more. Designed with toughness and comfort in mind, the lightweight mesh upper is abrasion resistant, and the EnduroFoam midsole, a nitrogen-infused supercritical foam, provides rebound shock absorption and returns energy to the foot. The grippy rubber Vibram® outsole utilizes Traction Lug technology and Megagrip traction for superior stability. The quick-dry GORE-TEX INVISIBLE FIT construction protects against wind and water and helps keep you on the trail in inclement weather. In addition, the foam-fabric tongue and gusset hug your instep to prevent unwelcomed hotspots.