This specific 3D model, "helmet high poly sculpt 3d printable ver 7 3D model 3D model 159", is an asset made available by "Unknown author".
Can be downloaded at "Unknown platform" by following the link.
Usage of this 3d asset is subject to the "Unknown license" agreement.
ZTL (Zbrush, filesize: 14.1 MB), OBJ (OBJ, filesize: 40.1 MB), STL (Stereolithography, filesize: 73.1 MB)