A credit card. The Bank of China Pi Card is a credit card inspired by the design of pi, which represents the meaning of infinite circulation and the lifestyle of cardholders pursuing excellence and perfection. The card offers a range of advertising campaigns and unique services to provide cardholders with a better and more convenient card experience. When using this card to make purchases, the points earned can be used to redeem gifts or cash coupons. Various online and offline promotions are also provided, including discounts, cashbacks, doubling of points, etc.