Although all the dual-currency credit cards of China Merchants Bank are RMB+USD, any credit card swiping machine in the world that supports international clearing organizations such as VISA, MASTERCARD or JCB can swipe China Merchants Bank's credit cards, because the euro consumption will be automatically converted into USD by the international clearing organizations. After returning to China, you can choose to repay in US dollars or RMB (purchasing foreign exchange for repayment).
Of course, if there is a local UnionPay credit card reader, it is more cost-effective to choose UnionPay POS credit card, because there is a UnionPay to convert euros into RMB for bookkeeping, and there is no foreign exchange process, so the exchange rate is more cost-effective.
If you have any questions, you can call the customer service hotline of China Merchants Bank Credit Card Center or go directly to the business outlets of China Merchants Bank for consultation. I hope my answer is helpful to you.