It is a Japanese braiding called "Kumihimo", Kumi meaning braid and himo meaning rope.
Historically, Kumihimo-style braided rope was used by samurai to attach their armor to their horses.
Three sizes to choose from:
Size S is suitable for a wrist circumference ranging from 14.5 to 16.5cm.
Size M is suitable for a wrist circumference of 17 to 19cm.
Size L is suitable for a wrist circumference ranging from 19.5 to 22cm.