Zoot Sports Men's Ultra Run Icefil Mesh Tee 62% Polyamide/36% Elastane/2% Carbon Imported Icefil combines Xylitol and thermal radiation nano technology, reducing skin temperature up to 5.4F/3C; Inset 1: 200g Icefil mesh back for enhanced ventilation and cooling Flatlock stitch construction ensures next-to-skin comfort and minimizes chafing