Under Armour HeatGear Flyweight Run Pant - SS15 HeatGear Flyweight - Provides breathability and added ventilation through mesh panels inserted throughout. Perforated Back Waist Panel - Delivers strategic ventilation. Moisture Transport System - Wicks sweat to keep you dry and light. Anti-odour Technology - Keeps your gear fresher for longer. Lightweight Stretch Construction - Improves mobility for a full range of motion.