Heat Generation: The fabric itself absorbs water vapor evaporating from the body and converts it into thermal energy, making the material warm. Heat Retention Moisture Absorption and Release Stretch Moisturizing Shape Retention Absorbs excess moisture inside the clothing and releases it to the outside, reducing the feeling of dampness. Stretch material provides an optimal fit. The elasticity makes it very comfortable to wear. Argan oil is kneaded into the fibers, providing a soft and moist touch to the skin. Special knitting achieves high elasticity and durability. Prevents shape loss from washing. This product is a joint development of (Stock) Uniqlo and To-shi. UNIQLO HEATTECH Ultra Warm Tights Kids Extra Warm Black