|Duofold Womens Original Mid Weight Long Sleeve Thermal Top KWM1 fiber content is 100% Cotton inside / 65% Cotton, 25% Merino wool, 10% Nylon outside. Duofold Womens Original Mid Weight Long Sleeve Thermal Top Duofold Originals created the base layer category with the first bi-ply thermals. Each style is constructed to offer unbelievably soft cotton against the skin, paired with the natural warmth of wool for superior thermal insulation. Duofold Originals . Duofold Womens KWM1 comes with 1 Thermal Tops per Pack.