3" Cuff Made with 75% Ultra-wicking M.D. Acrylic, 15% Nylon, and 10% Spandex for exceptional comfort and strength. ALL SockGuy socks feature their "Stretch-to-Fit" sizing system and exclusive "Easy-Fit" cuff for a PERFECT FIT every time on any foot. These features create superior softness and comfort and help eliminate blisters and hot spots. Other features include a double stitched heel & toe for added strength and durability. SockGuy delivers Superior Quality and High-Tech Comfort in every SockGuy sock they make - Guaranteed.