Engineered from ultra lightweight, moisture-wicking fabric, the 2XU Light Speed Tech Tee has zones of ventilation placed exactly where you need them, keeping you cool with every step. ULTIMATE COOLING Mesh ventilation zones are engineered into the chest and back, keeping you cool where you need it the most. ULTRA LIGHTWEIGHT Ultra lightweight engineered construction with clean cut bonding in key areas for a smooth finish so you can move freely. QUICK-DRYING Ultra fine polyester yarn provides rapid moisture dispersal to keep you cool and dry. BE SEEN Reflective logos and trims on shoulder, upper back and hem.