Jes.7z
This tool is intended for use with backups of games you already own.
Essential for making backups playable on certain PS2 modchips or software exploits like Free McBoot .
Generally high for standard Master Disc patches; mixed results for video mode forcing.
The ".7z" format indicates it is highly compressed using 7-Zip to keep the file size minimal. ⚖️ Performance Review Ease of Use
High. Features a simple "point and click" interface for patching ISOs.
“7-Zip fits a nice niche... and it is able to handle a large variety of file formats in the process.” Wikipedia
If you are looking at the file, you are likely dealing with the Just Enough Sony (JES) tool, a popular utility used by the PlayStation 2 homebrew community to patch and prepare game ISOs for various loaders. Direct Answer