Hilly Twin Skin Running Microsocks Meryl Skinlife - Contains built in anti-microbial technology and helps wick sweat and moisture away from the inner sock. LYCRA Sport - Stretch performance fabric in the outer sock, improves the fit and running comfort. Soft-Touch Reinforced Heel and Toe - Extra protection in key high-wear areas. Arch Grip Heel - Improves the fit of the sock, helping reduce irritation and slippage. Pre-Shrunk - For an improved fit.