Sorry, Only in Japan. Because using the Japanese Industrial Standards (JIS). This app is an app for measuring the size of the jewelry ring of Japan. Units of jewelry ring size of Japan is pronounced "gou". If you came to Japan, please try to use, such as in the case of considering the ring. ※ Warning: The accuracy of the scales cannot be guaranteed. Please be sure the calibration. ※:Use this application at your own risk. How to use 1. Select the size of the ring. 2. Display