It is a free, open-source tool available at the official 7-Zip website .
To see what is inside "syof.7z", you must extract it using a compatible utility: syof.7z
If you only want to see the filenames without extracting, select > Open archive . It is a free, open-source tool available at
Select > Extract Here or Extract to "syof/" to view the files in a new folder. It is a free
The 7z format typically offers a 30–70% higher compression ratio than the standard ZIP format.
This format can handle extremely large archives, theoretically up to 16 billion GB. How to Access the Content