Vault Protector coins were a type of Chinese numismatic charm coins created by Chinese mints.These coins were significantly larger,heavier and thicker than regular cash coins and were well-made as they were designed to occupy a special place within the treasury of the mint.The surface of the copper coin is engraved with“Da Tang Zhen Ku”,which translates as "the Vault Protector of the Tang Dynasty" and was cast during the Baoda period of Li Jing.