2.25 times warmer than regular HEATTECH. Ideal as an inner layer or as a T-shirt. – Bio-warming, insulating, moisturizing, and moisture-wicking comfort features. – Stretchy fabric holds its shape wear after wear. – HEATTECH Ultra Warm is 2.25 times warmer than regular HEATTECH, with a brushed finish for an extra soft feel. – We ’ve fine-tuned the body and cuff width for a versatile design that provides warmth up to your neck and looks great worn on its own or in layered looks. – This HEATTECH product contains no zinc.