Zoot Sports Men's Ultra 2.0 CRX Calf Sleeve 70% polyester/30% spandex with SilverTECH Imported NEW - NanoGLIDE yarn knit into heel and toe reduces blistering and hot spots and keeps feet drier and more comfortable NEW - NanoGLIDE yarn knit into heel and toe reduces blistering and hot spots and keeps feet drier and more comfortable|CRx = improved blood circulation|BIOwrap = targeted muscle stabilization|18-30mmHg compression level|