Light, soft, and more airy brushed lining. Ultra Stretch fabric stretches with your movements for exceptional comfort. 2.25 times* warmer than our regular 'HEATTECH'. *Based on CLO values, which indicate the thermal insulation of clothing. In comparison with standard 'HEATTECH.' Wicks away moisture to keep you feeling fresh. Features a silhouette that feels like a long-sleeve T-shirt or sweatshirt and styles on its own. 33% Polyester, 32% Acrylic, 21% Rayon, 14% Spandex ( 33% Uses Recycled Polyester Fiber )