A warmer version of the classic Swix baselayer, the RaceX Merino 1/2-Zip Top features body-mapping and a special knit to perform during high-intensity activities. It combines two types of knit to maximize warmth and our freedom of movement, and the special yarn wraps merino wool around a nylon core for a soft, durable, and moisture-wicking layer of insulation next to our skin. This lets us exercise in comfort or enjoy this performance fabric for casual, everyday wear.