The product comes in full range RGB .exr and HDR formats which are the best for HDR images.
The Exr and HDR formats resolutions:
16384x8192
8192x4096
4096x2048
2048x1024
You will also get a Blend file with Environment texture set up.
Please keep in mind that HDRI is an image, not 3D model.
The HDRI was made using my scene which can be found here:
https://www.artstation.com/a/10331570
After purchase you’ll get my full support if needed.
Thank you! Have a nice day! :)