Under Armour Base 3.0 Half Zip Top ColdGear accomplishes the impossible: it keeps you warm without weighing you down ArmourBlock technology neutralizes the microbes that cause odor before there is any odor a Raglan sleeve construction - allows for total mobility and a full range of motion, while e Flatlock Seams - reduce any rubbing or chaffing that regular seams can cause meaning a mor Ergonomic Side Seams - with mesh fabric make the garment breathable and reduces the chance