THESE SOCKS PROVIDE UNMATCHED COMFORT AND PERFORMANCE. WITH COOLMAX® FOR WICKING, NYLON AND RUBBER FOR STRENGTH, AND SPANDEX FOR COMFORT, THIS SOCK IS AN INTEGRAL PART OF THE SHOCK MITIGATION SYSTEM™ TECHNOLOGY. 5.11's SOCKS HAVE 12 ZONES OF VARYING COMPRESSION AND FABRIC BLENDS FOR INCREASED BLOOD CIRCULATION, HEAT REDUCTION, ADDED STRESS RELIEF, COMFORT, AND RESILIENCY. 5.11 PUTS A LOT OF ENGINEERING BEHIND EVEN THE SMALLEST DETAILS TO HELP YOU PERFORM AT YOUR BEST.