Hilly Energize Classic Running Socks NanoGlide - One of the worlds most friction free fibres. Celliant Technology - Modifies visible and infrared light, recycling back to the body increasing blood flow and tissue oxygen levels Vented Upper - Allows air to permeate the exterior, delivering breathability within. Anatomical Cushioning - At mid-level. Fabric Composition: 43% Polyester (Celliant), 32% Polyamide, 14% Polyamide (Nanoglide), 8% Cotton, 3% Elastane (Lycra Sport)