Rooster PolyPro™ is constructed from a combination of Polypropylene (94%) and Elastane (6%). We've brushed the inner fabric surface to give it a thick, fleece-like, high quality texture which feels incredibly warm and soft next to your skin. The resulting garments provides excellent thermal qualities making it the perfect base layer. Polypropylene is naturally hydrophobic, which means the fabric feels remarkably dry, even when wet. These are a liner and should not be used in load conditions without normal glove protection.