1.Please allow a little color error .
2.Please allow manual measuring permissible error.
3.Not all phones are universal, please read the introduction carefully before buying.
Function 1:accessories,Fashion jewelry, couple rings.
Function 2:Android or WINDOWS have NFC mobile phone can be used(unlock the phone, information sharing, card sharing, etc.) NFC chip embedded in the outside of the tiles.
Note:Try to keep the rope more tension when measure your finger size, too big size ring will slip off easily.