The model was created using Blender, version 4.3. The model is a high-poly solid with N-sided faces, allowing for further subdivision. Texture details (jaw strap, NVG lanyard, elastic braided straps, Velcro, etc., see screenshots for details) were achieved using the Displacement modifier and the Decimate modifier. The modifiers are retained for easy modification. Displacement is resource-intensive; the modifiers are enabled by default with the viewport closed. With Displacement and Decimal enabled, the total face count is 2,842,036.
Except for the parts using Displacement, the model is not UV-coded. Personally, I find Blender's Decimate modifier easier to use than Zbursh's Decimation Master; however, switching the editor on and off can cause a slight lag, so be prepared.
The file includes materials and lighting.

The helmet visor is a detachable part of the model and has a one-click show/hide switch; see screenshots for details.
The model is exported in Obj and FBX formats, with two versions. Both exported models have the subdivision modifier disabled; the difference lies in one version that outputs a model with Displacement and Decimate modifiers applied.