This specific 3D model, "metal stairs 3D model get", is an asset made available by "Unknown author".
You can download this asset for free at "Unknown platform" by following the link.
The licensing terms for this digital asset are governed by "Unknown license".
STL (Stereolithography, filesize: 65 KB), OBJ (OBJ, filesize: 78.2 KB), 3DS (3D Studio, filesize: 29.7 KB), DAE (Collada, filesize: 144 KB), FBX (Autodesk FBX, filesize: 82.5 KB), IGE (IGES, filesize: 299 Bytes), MAX (Autodesk 3ds Max, filesize: 75.9 KB), SKP (Sketchup, filesize: 173 KB), OTHER (Other, filesize: 21.2 KB)