Athleta Foothill Seamless Open Back Tank Top White Sleeveless Flowy Vented XS /S Size Extra Small /Small based off of measurements, inner sizing has worn off - Perforated detailing around the arms and down the front for breathability. - Slit back that can be tied or left down. - 100% Nylon. - Buttery soft material. Very good condition! Please see all photos for details and measurements