Crown of thorns ring ready to print, four size model. inner diameter: -16.55mm -17.5mm -18.1mm -18.80mm approximative metal weight: 18kt 17.5mm(3.2gr) 18.1mm(3.7gr) 18.80(4.00gr) 16.55mm(2.80gr) model made using rhinoceros and zbrush .stl printable format available, please contact us for any question or different size. thank you!!