collaborated with a retro leather goods brand to customize hardware hinges for retro briefcases. Made of H62 brass through precision casting and antiquing oxidation processes, the surface presents a retro bronze color with a heavy and high-end texture. The silent rotating shaft design allows the briefcase to be opened and closed without harsh noise. The reinforced rivets firmly fix the hinges and the bag body, which can bear 30kg and easily support a briefcase full of documents. The hinges are suitable for briefcases of different sizes, fitting the lines of the bag body after installation without destroying the overall retro beauty. This hinge helped the partner increase the premium of briefcases by 25% and become a hit accessory for retro leather goods.