Description:Material: AlloyInner Ring diameter: about 16mm/17mm/18mm/19mm/20mm (Each Pieces)Size: US Size:6-10 ; UK Size: L 1/2 - V 1/2Width: 6mmThe ring will change color according to the temperature of your body. Very funny and amazingPackage Includes:20 Pieces Mood Rings1 Piece Color CardNote:Since the size above is measured by hand, the size of the actual item you received could be slightly different from the size above. Meanwhile, please be reminded that due to lighting effects, monitor's brightness / contrast settings etc. there could be some slight differences in the color of the pictures and the actual item.