Small. The description says they fit wrist circumference of 5.x” to 7.x”. I have skinny wrists as an adult male and only 5/8” is left beyond the buckle. The band is so slippery, the little keeper doesn’t have any “bite,” and the tag end being 5/8,” causes the keeper to slip completely off, leaving the band secured by (only) the buckle. Once that happens, the buckle can “hinge” and loosen.