90/10 nylon/spandex with StretchFlex�,Athletic Heather, Heather Navy, and Safety colors are 90/10 polyester/spandex,Dark Grey Heather is 50/40/10 nylon/polyester/spandex,Moisture wicking and anti-microbial,Double-layer with folded edges,Flatlock stitch and back seam,Tear away label