Smart ring size 10 water proof

Brand new smart ring. Size 10. Too big for me. I bought on sale that’s why it’s not too expensive. Took the risk but it doesn’t fit. Has app, is water proof, measures different metrics. Like sleep and heart rate It is clearly good quality, made of glass and comes with the correct charging cord. Size 10 is 62-64mm around your finger. Measure with a string. I clearly measured my finger around 60-61 thinking it would fit but it does not. So closer to 63-64mm