The Under Armour Boy's Coldgear Evo Fitted Baselayer Mock is fitted to lay close without the squeeze of compression. It has a slick outer layer allows easy layering and the warm, brushed inner layer offers both soft comfort and incredible heat-trapping performance. The fabric is a four way stretch allows for a full range of motion. It has under armour’s signature moisture transport system to keep you dry and anti-odor technology to keep this shirt fresh longer.