PRIMALOFT® wool sock. Similar performance to the feather regarding lightness ratio and breathability. PRIMALOFT® performs the thermal compensation process, its doesn't overheat the foot while holding it at proper temperature in any condition. Water-repellent fiber. Two layers sock. PRIMALOFT® inner layer keeping the inteligent fiber in contact with the skin. Polyamide outer layers which offers resistance against impacts ad scarfs. Elastic band on the foot to prevent blisters or abrasions.