Under Armour HG Flyweight Running Top Heat Gear Fabric - Ideal for use in warm days and in gyms. Moisture Transport System - Wicks sweat away from the body, keeping you feeling cool and comfortable. Anti-Odour Technology - Keeps your gear fresh during workouts and in between uses. Ultra-Light, Smooth Fabric - Provides extreme comfort and quick dry performance. Mesh Side and Underarm Panels - Provide strategic ventilation.