The XT 5 FW Ski Boot pairs Polyester Thinsulate insulation with a lace cover that keeps snow from working its way in over a long day on the trail. A 3D injection high cuff adds free-moving support at the ankle without locking down the stride a classic kick-glide motion needs. The boot mounts to NNN, Turnamic, and Prolink binding systems, so a boot swap doesn't force a binding change, too. What Our Gearhead(R) Experts Are Saying:"I hit a rutted, ungroomed stretch on my usual loop last week, and the tall cuff held my ankle steady through the uneven snow instead of letting it roll the way a low-cut boot would. It's the first classic boot that hasn't made me second-guess leaving the packed track."