Convenient sizing kit includes multiple sizing options, helping users to easily find their perfect Galaxy ring size (availability of Galaxy ring sizes and colours may vary by country/region) Users should wear sample rings for at least 24 hours (even during sleep), which helps to determine if the size is appropriate for everyday use Sample rings have three bumps on the inner side that indicate where the sensors are located on the actual Galaxy ring Users are instructed to ensure these bumps face their palm while wearing the ring Galaxy ring sizes differ from regular ring sizes, and the users have to follow the instructions provided to find the perfect fit (Sample rings included in the Galaxy ring sizing kit are non-functional and are intended solely for measuring your ring size) Galaxy ring sizes range from 5 to 13, without half sizes (Galaxy ring sizes are based on the US standard sizes (5 to 3))