The surface of the ruler has a small magnifying glass to make the reading more convenient and accurate, so that you can better understand your finger size.
The American size of 1-17 can be measured simply by wearing it on your hand and adjusting it to fit. And you can see the scale clearly
1-17 American size, finger size from 1 to 17, accurate and clear with the aid of magnifying glass, not only can be used as a ring size reference, but also can be used for measurement of other jewelry.