EXPLORE THE GREAT OUTDOORS IN THE XPS EXPEDITION 3.0 THERMAL MOCK NECK.Have maximum warmth but minimal bulk when you wear the XPS Expedition 3.0 Thermal Mock Neck. Thanks to hollow core micropolyester yarn, you can do just that. And thanks to X-Odor technology, you can experience the great outdoors to your greatest ability without having to worry about letting any smells sneak through. Don't let anything get you down. FEATURESX-Odor-