This specific 3D model, "Kids Heart Pendants 3dm STL OBJ FBX Renders Details 3D print model 7", is an asset made available by "Unknown author".
You can download this asset for free at "Unknown platform" by following the link.
The license for this digital asset is "Unknown license".
STL (Stereolithography, filesize: 887 KB), OBJ (OBJ, filesize: 2.35 MB), 3DM (Rhinoceros 3D, filesize: 1.18 MB), FBX (Autodesk FBX, filesize: 408 KB)