Coin strings are one of the oldest doorway ornaments in Chinese homes. The nine-coin version threads replicas of the cash coins of nine different Qing reigns onto a single cord, the number nine chosen because it is the largest single digit and reads as "long-lasting." The coins here are brass castings made from traditional moulds. They carry no historical value and are sold purely as decoration.
Hang it where it will not be knocked — beside a door frame, on a hallway wall, or over a shop counter. Because the piece is brass, it will develop a soft patina over time; a dry cloth is enough to bring back the shine.