They can squeeze data into a smaller footprint than a standard Zip.
If you extract the file and see a .exe or .scr inside that you weren't expecting, do not run it . T31.rar
To help me tailor this further, could you tell me or what device you think it belongs to? I can help you verify if the source is legitimate. What is a RAR file? They can squeeze data into a smaller footprint
They are frequently password-protected to keep contents secure during transit. T31.rar