Women's Paradox Performance Zip-Up Long Sleeve Base Layer Cover to hold 1/4" zipper in place and thumb holes for layering and extra insulation Structured material made with 92% Polyester and 8% Spandex Patented Dri-Release and Anit- Odor wicking material for high intensity workouts Stretch, lightweight top provides comfortable warmth without the itchiness fleece like lining is perfect for all outdoor activities in the winter cold!