Material: High-Quality Solid 925 Sterling Silver (Nickel-Free and Lead-Free)Stones: Cubic ZirconiaColors: Silver and Gold Sizes: US 5.25, 6, 6.5, 7, 7.75, 8, 8.5, 9, 9.5 (UK K, L1/2, M1/2, N1/2, P, P1/2, R1/2, S1/2), or Open Back (Adjustable and Suitable for US Sizes 3-10) Size 5.25 = 15.9mm in Diameter or 50.0mm in Circumference Size 6 = 16.5mm in Diameter or 51.9mm in CircumferenceSize 6.5 = 16.9mm in Diameter or 53.1mm in Circumference Size 7 = 17.3mm in Diameter or 54.4mm in CircumferenceSiz