Fly Racing Dirt Heavyweight Base Layer Top Fly Racing's Heavyweight Base Layer Top ensures a warm yet comfortable experience with its quick-drying, moisture-wicking fabric. The flat-lock seam construction is designed for ultimate comfort, while the stretchy material maintains range of motion. Built-in with UPF 40+ sun protection, and Polygiene technology which effectively controls odor. It promises to keep you fresh, even after a whole day of riding. Features: Extra warm fabric that still wicks moisture fast and dries quick Flat-lock stitch seam construction Multi-direction stretch fabric allows for un-restricted range of motion UPF 40+ sun protection Polygiene odor control technology Ergonomic panels are form fitting (non-compression)