"Proto" series The series is named Proto, which means "early" or "prototype". A metal bangle full of profound feeling. It is an elegant design that stands out for the goodness of the material because it is simple. Due to its volume and large surface, it reflects light beautifully and gives a sophisticated impression to the arm. Because of the plain details that are easy to match regardless of styling taste, it is an item that can be used by both men and women. K18 is coated on top of SILVER925 (sterling silver) and the high quality of metal is added, so you can use it as a higher-grade gold color.