The materials are balls and catches brass and others are stainless steel.It's a catch expression.Please connect the part to the Kan and use it. *This is an accessory, so you may change the color by incorporating the changes in the fashion.Also, in the process of processing, dark shades of color may occur without prior notice.(Depending on the part, there may be a variety of other parts and colors.) * As soon as the inventory is out of stock, the replacement will return to the existing product.Please be careful.