The "3DM 70 ENGAGEMENT RING FILES 3D Model Pack purchase" 3D asset is currently listed under the authorship of "Unknown author".
Can be downloaded at "Unknown platform" by following the link.
This specific 3D model is provided under the "Unknown license" framework.
STL (Stereolithography, filesize: 934 MB), OBJ (OBJ, filesize: 74.2 MB), 3DM (Rhinoceros 3D, filesize: 1.55 GB), FBX (Autodesk FBX, filesize: 11 MB)