Sport-Tek Heather Contender Tee. ST360 100% Polyester Ultra breathability meets an excellent snag-resistant, heathered appearance at an equally great value. 3.8-ounce, 100% polyester jersey Removable tag for comfort and relabeling Set-in sleeves *Due to the nature of 100% polyester performance fabrics, special care must be taken throughout the screen printing process.