This specific 3D model, "Military Outfit - T-shirt Low-poly 3D model 58", is an asset made available by "Unknown author".
You can download this asset for free at "Unknown platform" by following the link.
Usage of this 3d asset is subject to the "Unknown license" agreement.
STL (Stereolithography, filesize: 162 KB), OBJ (OBJ, filesize: 169 KB), BLEND (Blender, filesize: 1.13 MB), C4D (Cinema 4D, filesize: 216 KB), DAE (Collada, filesize: 813 KB), 3DS (3D Studio, filesize: 86.5 KB), MAX (Autodesk 3ds Max, filesize: 293 KB), FBX (Autodesk FBX, filesize: 1.82 MB), FBM (fbm, filesize: 1.82 MB), DWG (AutoCAD, filesize: 326 KB), GLTF (glTF, filesize: 755 KB), MA (Autodesk Maya, filesize: 253 KB), ZPAC (Marvelous Designer, filesize: 3.81 MB), 3DM (Rhinoceros 3D, filesize: 240 KB), UNITYPACKAGE (Unity 3D, filesize: 179 KB), SKP (Sketchup, filesize: 1.45 MB)