MIL-TEC BLACK THINSULATE SNOW BOOTS. Upper: lower area: Rubber upper area: 100% Cowhide Lining: lower area: Thinsulate Insulation upper area: 100% Polyester Outsole: Rubber Shoelace: 100% Polyester – waterproof foot area – replaceable inner lining – upholstered leg – treaded sole with nubs – 8-eyelet lacing.