SPECS: Adult cross country ski boots Ideal for on-trail performance Intended for groomed or ungroomed surfaces Neoprene-covered laces Mid to lightweight insulation for added warmth NNN BC: larger toe bar with 2 wider grooves on boot's sole Only compatible with PROLINK, NNN, and Turnamic DESIGN & TECHNOLOGY: Thinsulate(TM) liner keeps your feet warm in cool conditions SensiFit(TM) technology allows for an articulated fit and ensures ultimate comfort Laces, front zipper, and adjustable outer Velcro closure ensure that your boots stay on Integrated hooks allow you to attach gaiters to the boots and protect you from the snow Smart structure cuff provides extra support around your ankle Comfi Flex chassis offers maximum range of motion Quicklace(TM) one-pull system for added convenience with durable Kevlar laces