Stay Strong sports performance socks are purpose-built and functionally fashionable. They include a "Stretch-to-Fit" sizing system and an exclusive "Easy-fit" cuff for a perfect fit every time on any foot. These features create superior softness and comfort to help eliminate blisters and hot spots. They also feature a double stitched heel & toe for added strength and durability. S/M - UK 3 (EU35/US4) - UK7 (EU40/US8). L/XL - UK7.5 (EU41/UK8.5) - UK11 (EU46/US12).