The Nike Lightweight Training Socks feature stretchy fabric for snug comfort and breathability. Snug and Secure An arch band provides snug comfort and helps prevent the sock from bunching. More Details Micro-nylon and elastane fabrics provide a soft feel Interior anti-slip silicone heel pad helps keep sock in place Fabric: 57% nylon/40% polyester/3% elastane Machine wash Imported Stay Dry Dri-FIT Technology wicks sweat away from your skin to help keep you dry and comfortable.