The ring is available in three sizes - US6(16.5mm),US7 1/4(17.5mm), US8 1/2 (18/5mm),other sizes on request Metal weight about 14K-10gramm,18K-17gramm Gem round 5.0mm Models fixed with RP Magics software and ready for prototyping on CNC or any 3D Printing. .Stl file is for printing and 3DM source file for editing or modifying.Tested in production. If you have any questions or suggestions please contact me.