Sport-Tek PosiCharge RacerMesh Polo. ST640Thanks to our ultra-fine flat back RacerMesh, this polo has unparalleled breathability for superior cooling. PosiCharge technology locks in color and keeps logos crisp-making this value-priced essential a fan favorite all season long., 3.8-ounce, 100% polyester flat back mesh with PosiCharge technology, Tag-free label, Moisture-wicking, Flat knit collar, Taped neck, 3-button placket with dyed-to-match buttons, Set-in, open hem sleeves