The Nitro Max stands out and stands supremely comfortable with our premium NITRO? technology built right in. This lightweight combination of flexibility and support cushions and stabilizes the foot for optimal performance. NITRO™ stabilizing frame for support with forefoot flexibility. Shock Shield® diffuses heel strike impact to minimize fatigue. Removable NITRO™ insole for shock absorption and rebound. Duratread™ sole with rider-tested traction zones. Full-length elasticized panel on lateral side. Mobility notch. Lightweight chassis for heel and mid-foot torsional stability. Full length. premium quality coiled YKK® zipper.