For the backcountry, ski touring or for a low volume custom boot, this sock is a game changer. The unrivaled ankle compression fit for zero slip minimizes the risk of heel/ankle chafing and blisters. It's the ultimate basic setup for freeride ski touring. Engineered use of Nanoglide anti-friction Teflon/PTFE yarn in heel and ankle - further improving heel/ankle comfort and preventing blisters when hiking.