If you want to buy a proposal ring and want to know what size ring your girlfriend is wearing, you can make a rough estimate, and then know her finger size according to the circumference or diameter, or take a photo of her hand directly, and then ask the staff of the jewelry store to help you estimate her finger size. In fact, the most important sincerity in proposing marriage is to let her know and feel that you really love her. You can wear a Darry Ring ring that needs to be customized by a man with his ID card, and you can only customize one for the person you like in your life. It has the romantic meaning of "the only true love in your life" and gave her a lifelong commitment. Then I think even if the ring size you finally choose is not completely correct, I don't think your girlfriend should mind too much.