hmkcc.hk

https://hmkcc.hk/%E5%98%89%E5%BE%B7%E7%A7%8B%E6%8B%8D%EF%BC%9A%E5%A2%9E%E8%A8%AD%E7%9F%B3%E9%95%B7%E6%9C%89%E5%85%88%E7%94%9F%E9%8C%A2%E8%8E%8A%E7%A5%A8%E6%94%B6%E8%97%8F%E5%B0%88%E5%A0%B4/

Wikipedia: String of cash coins (currency unit)