This collection of rings is ready for 3D printing.Ring sizes 16 16.5 17 17.5 18 18.5 19 19.5 20 20.5 21 mm. Approximate weight of rings by size(GOLD 14K): 16mm-7.33g 16.5mm-7.55g 17mm-7.76g 17.5mm-7.97g 18mm-8.19g 18.5mm-8.4g 19mm-8.62g 19.5mm-8.83g 20mm-9.04g 20.5mm-9.26g 21mm-9.47g. Width: 5.6mm.