TCA Men's & Boy's HyperFusion Compression Base Layer Shirt Long Sleeve Under Shirt&nbsp;- Mock Neck/Crew Neck TCA compression fit improves muscle power and endurance Flat lock seams eliminate skin irritation Breathable fabric regulates body temperature for higher performance in all conditions Moisture wicking fabric is QuickDry and absorbs sweat from the skin keeping you dry and comfortable 3DAirMesh panels provide strategic ventilation in high heat zones