shell helmet 3D model is available on CGTrader for $12. Original author: jwolf73.
BLEND (Blender, filesize: 21.7 MB), OBJ (OBJ, filesize: 7.86 MB), FBX (Autodesk FBX, filesize: 10.5 MB), JPG (JPG, filesize: 21.7 MB), OTHER (Other, filesize: 38 MB), STL (Stereolithography, filesize: 8.27 MB), TEXTURES (Textures, filesize: 11.4 MB)