A model of Iron Man's head/helmet available in multiple formats.
This was originally modelled and rendered in Blender 3D so only the .blend format has the materials and the lighting setup. The other formats contain only the geometry and the circuitry texture that is in the gap in the cheek (see close-up preview image).
The brushed metal effect was created procedurally in Blender with nodes so the texture is not included in formats other than .blend.
The materials in the .blend are created with nodes with the Cycles renderer.