The Salomon RC8 Prolink is an excellent cross country ski boot for athletic skiers looking for performance on the groomed tracks when skiing in the classic style or very light skating. An Optimized Classic Flex offers you a feel for the snow and added control over your skis. An Adjustable Heel Strap allows you to fine tune the fit to prevent any heel slippage. Thinsulate Insulation in the Custom Fit Liner offers you warmth with a fit that can be molded to your foot. Salomon's Hyper Soft 5mm Insole cushions and supports your foot all day on the trails. Optimized Classic Flex, Adjustable Heel Strap, Thinsulate Insulation, Custom Fit Liner, Internal Thermo Formed Heel Counter, Lace Cover with Diagonal Zip, Hyper Soft 5mm Insole, COMPATIBLE WITH PROLINK, TURNAMIC AND NNN BINDINGS, Warranty: One Year, XC Ski Best Use: Groomed, Compatible Binding System: NNN, External Frame: No, Covered Laces: Yes, Insulation Material: Thinsulate, Ski Gear Intended Use: Cross Country, Support: On Trail Performance, Warmth: Warmest, Skill Range: Advanced Intermediate - Expert, Model Year: 2019, Product ID: 530867, Model Number: L40556100075, GTIN: 0889645661544