Under Armour HeatGear Flyweight Run Singlet Running Vest Signature Moisture Transport System - The fabric actively works to wick swear away and out of the garment, keeping you dry and cool. Mesh Ventilation - For enhanced breathability giving you critical airflow in high-heat areas. Athletic Cut - The garment is designed with a slimmer fit to enhance comfort and reduce garment bulk. HeatGear - Under Armour's technical product range for the summer season. Wear this to stay light, dry and cool. Anti-Odor - The garment is made with an anti-microbial treatment to help keep you fresh.