Lock charms are shaped like ancient Chinese security locks. Their shape resembles a basket or in most cases the Chinese character for “concave” (凹). The pendants tend to be flat, without any moving parts, or the functionality of the locks they symbolize. They are decorated with both Chinese characters and symbols. Like other types of Chinese numismatic charms, lock charms are meant to protect the wearers from harm, misfortune, and evil spirits, and to bless them with good luck, longevity, and a high rank.