The Hermès Kelly Double Tour Bracelet is also known as the no less stylish yet considerably more affordable younger sister of the much pricier Hermès Collier de Chien.
Originally made for women but today worn by both genders, the Kelly Double Tour Bracelet comes in 4 different sizes (XS, S, M and L). As far as the size is concerned, S is 5.5 cm in diameter, while M is 6 cm in diameter, which should give you a pretty good idea as far as the sizing available is concerned.