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 Max Tall Riding Boot Product Features : NITRO™ stabilizing frame for support with forefoot flexibilityShock Shield® diffuses heel strike impact to minimize fatigue, Premium full-grain leather upper with oiled inner calf panel, Removable NITRO™ insole for shock absorption and rebound, Duratread™ sole with rider-tested traction zones, Full-length elasticized panel on lateral side, Mobility notchLightweight chassis for heel and mid-foot torsional stability, Full lengthpremium quality coiled YKK® zipper Men's Nitro Max Tall Riding Boots in Black, Size: 10 D Medium Slim by Ariat