The 1000 Mile Wool Fusion Walking Sock combines 1000 mile's famous double layer blister free construction with extra padded comfort zones. Double layer construction eliminates friction between the foot and shoe, reducing wear and preventing blisters. Around the achilles tendon is full length padding for extra protection along with extra padded comfort zones on the toe, heel and ball of the foot.Outer layer:30% merino wool_46% nylon_23% cotton_1% elastaneInner layer:_100% Tactel