This collection of rings is ready for 3D printing.Ring sizes 16 16.5 17 17.5 18 18.5 19 19.5 20 mm. Approximate weight of rings by size(GOLD 14K): 16mm-1.53g 16.5mm-1.58g 17mm-1.62g 17.5mm-1.66g 18mm-1.7g 18.5mm-1.75g 19mm-1.79g 19.5mm-1.83g 20mm-1.87g.