The Fischer XC Control NNN Cross Country Ski Boots offer stability and control for experienced or athletic skiers who prefer groomer and lightly ungroomed terrain. A Thermo-Moldable Fit allows for the liner to be heated and molded for a customized fit. An Ankle Support Cuff and External Injected Heel Cap help drive energy towards your skis and prevent any heel slippage. Comfort Guard Insulation keeps your feet warm and toasty when you are out in the woods on frigid days when the snow is good. Fischer's Triple F Membrane is highly waterproof and breathable to keep you out gliding. Ankle Support Cuff, Thermo-Moldable Fit, Comfort Guard Insulation, Fischer Fresh, Injected Exterior Heel Cap, COMPATIBLE WITH PROLINK, TURNAMIC AND NNN BINDINGS, Warranty: One Year, XC Ski Best Use: Groomed/Ungroomed, Compatible Binding System: NNN, External Frame: Yes, Covered Laces: Yes, Insulation Material: Synthetic, Ski Gear Intended Use: Cross Country, Support: On Trail Performance, Warmth: Warmer, Skill Range: Intermediate - Advanced, Model Year: 2022, Product ID: 580602, Model Number: S20519-40, GTIN: 9002972430329