Check out JEWELCAD 45 RING FILES 3D Model Pack 3D model on CGTrader for $39.99. High-quality mesh by gems-herra.
STL (Stereolithography, filesize: 1.23 MB), JCAD (JewelCAD, filesize: 4.45 MB), IGE (IGES, filesize: 6.18 MB), DXF (DXF, filesize: 27.2 MB)