50% Nylon, 14% Lycra Spandex, 23% Wick Poly, 13% Cotton Second Skin-Our most technologically advanced socks. Utilizing 3-Dimensional modeling, Thirty48 has designed them for Anatomically Correct Fit. Engineered with Stretchy Ultra Light Fabric for Seamless Toe Closure (50% Nylon, 14% Lycra Spandex). Seamless Toe Closure allows for complete range of movement and prevents abrasion on the toes. Moisture Wicking Lightweight Mesh (23% Wick Poly, 14% Lycra Spandex, 13% Cotton) provides superior ventilation and comfort. Heel pull tab for easy On and Off. THIRTY48 IS THE MANUFACTURER – You can buy with confidence knowing that your purchase is directly from THIRTY48 Corp. Our customer service team is available 24/7 and there is no third party department you have to deal with since you are buying direct from Manufacturer. Thirty48 will NOT be responsible for any purchase made from other sellers as they are NOT selling the real Thirty48 Ultralight Running Socks.