An all-new ultra-insulated winter sock platform engineered with a wool textile blend and reinforced with increased insulation in critical areas. Breathable ultrasoft and warm - total comfort for winter's harshest conditions. The Ultraz FUGU hearkens back to the warmest most protective line of winter equipment in ASSOS history so it's fitting to bring back for our most thermoregulating socks. The wool blend creates micropockets of warm air beneath the protective layer of your booties with increased insulation across the toe and the front of the sock. The ultra-high 31cm 16in cuff extends that protection to eliminate gaps between the FUGU and winter tights. Ultra Insulation Ultrasoft merino woool blend provides extreme insulation for the coldest conditions Thermoboost Increased insulation on toe and shin for more protection at the most vulnerable areas. Permanent Odor Control The natural antimicrobial properties of wool resist the accumulation of odors.