This sneaky sock lives up to its name. Whether in flats or your favorite sneakers, the Undercover, by SockWell, stays hidden and stays on all-day long! FEATURES Spandex Throughout The Sock Turn Welt Top Y-Heel Construction Moisture Wicking Seamless Toe Closure 30% Merino Wool 30% Rayon From Bamboo 35% Stretch Nylon 5% Spandex PRODUCT DETAILS Sock Type: No Show Socks Fitting: Women's Small/Medium - Shoe sizes 4 – 7.5 (European Sizing 35 – 38) Women's Medium/Large - Shoe sizes 8 – 11 (European Sizing 39 – 43) Men's Medium/Large - Shoe sizes 7-10 (European Sizing 39 - 43) Men's Large/X-Large - 10.5 – 13 (European Sizing 44 – 47) Men's XX-Large - 13.5 – 16 (European Sizing 48 – 50)