The Smartwool Ph D Outdoor Light Crew sock has been made from New Zealand Zque Merino wool & is Smartwool's most versatile outdoor sock. It features WOW (Wool On Wool) technology in high density impact zones for greater shock absorption & durability, while the 4-Degree Fit System keeps the sock in place.FABRICS:77% Merino wool/22% Nylon/1% Elastic.GLOSSARY: Merino Wool: Wool from Merino sheep that provides good insulation, durability, odour resistance & odour control.