Under Armour Tech HeatGear Short Sleeve T-Shirt Synthetic Lightweight UA Tech fabric - a softer, more natural feel for superior comfort. 4-way stretch fabrication - improves mobility, while helping to maintain shape. Signature Moisture Transport System - wicks sweat away from the body, keeping you cooler and drier. Loose Fit - Full, loose fit for enhanced range of motion and breathable comfort no matter where your workout takes you. Heatgear - For when it's hot. Keeping athletes cool and dry. Lightweight, high-performance fabric maximizes comfort and breathability.