High-resolution texture packs or "Total Conversion" (TC) mods for games.

The file is a specific part of a multi-volume compressed archive. Based on its naming convention, it is the fourth segment of a larger file that has been split to make it easier to download or store. Understanding Multi-Part Archives

You cannot open the .004 file by itself. To access the content inside, you must follow these steps:

The .7z indicates it is a 7-Zip archive, and the .004 indicates it is the fourth part .

While the specific contents depend on the source of your download, filenames following the Tc-Aran or Tc- prefix are frequently associated with:

Large datasets or firmware repositories.