The key to thermal regulation in cold weather is moisture management. The Chrono™ Long Sleeve Base Layer is engineered with our proprietary Wikpro™ fabric in a seamless construction to keep you warm, dry, and comfortable in cold, damp conditions. Wikpro is a proprietary blend of polypropylene and nylon knit that enhances moisture transfer while staying soft against the skin and providing great rebound and fit. This is the same fabric proven in our popular Chrono SL Base Layer, but constructed in a heavier weight for extra insulation.​​