The Velocity is fully seam sealed with a Z-Lining membrane that is waterproof and breathable and has a  10,000mm/8,000g DuPont™ Tefl on® fi nish. It also has an Outlast® fleece/tricot lining that will regulate your temperature.  Detachable lining system zipper allows you to zip in the Yamaha liner (sold seperately) for extra added warmth.