While the specific contents of a .7z file depend on its source, archives with this naming convention for rail simulators often include:
Is Simrail What Tsw Should Have Been? - Dovetail Games Forums
: Various historical and modern PKP color schemes.
: Interior models of the driver’s desk and controls. How to Access the Content
: Most simulator mods require the extracted folder to be placed in the Assets or Mods directory of the game's installation path.
: Since the file ends in .7z , you will need a tool like 7-Zip or WinRAR to open and extract the data.