90% Polyester, 10% Elastane. The Under Armour HeatGear Armour CoolSwitch Womens Tank offers exceptional breathability to regulate your temperature as you train. Made with an Incredibly light allover pinhole mesh for unrivalled breathability. CoolSwitch technology uses an exclusive coating on the inside that pulls heat away from your skin to feel cooler as you train. Lightweight Material wicks sweat and dries quicker. Shaped hem delivers enhanced coverage and perfect fit with Rolled forward side seams with bartack detail. Minimal modern T-back construction with Branded elastic accent. Finished off with Under Armour logo accents. Fit: Fitted. Scoop neck, Sleeveless design, CoolSwitch technology, Moisture Transport System wicks sweat, Racer back for greater range of motion.