Sport-Tek Tall PosiCharge Competitor Tee. TST350 100% Polyester Lightweight, roomy and highly breathable, these moisture-wicking, value-priced tees feature PosiCharge technology to lock in color and prevent logos from fading. 3.8-ounce, 100% polyester interlock with PosiCharge technology Removable tag for comfort and relabeling Set-in sleeves