Features: ,The ring will change color according to the temperature of your body. Very funny and amazing!,Color change with temperature, the temperature below 14 degrees the ring is black, and 14-38 degrees the ring change various colors,,Material: Alloy,Color: Multi-Color,Package include:1 pcs rings,,Style1 size:,            CN:16 / 17 / 18 / 19 / 20,            US: 8 / 8.5 / 9 / 9.5 / 10,Style2 size:,            Free size,Ring diameter:17mm(Adjustable),~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~,NOTICE:,    1. Please allow 1-3 mm tolerance due to manual measurement.,    2. Different displays show the same picture may be slightly differences.,,       Thx for understanding,hope you a happy life.   :)