V4.39.10_psdzdata.7z Here

The .7z extension indicates that the archive was compressed using the 7-Zip utility. Because the "Full" version of this database can easily exceed 200 gigabytes, high-ratio compression is required to distribute the files over the internet.

💡 If you run both E-Sys and ISTA on your machine, you can save massive amounts of hard drive space by placing the PSdZData files in your ISTA directory and creating a Windows symlink (shortcut) pointing to the E-Sys data folder. Important Safety Warning v4.39.10_PSdZData.7z

When downloading files like v4.39.10_PSdZData.7z , users generally encounter two distinct packages: users generally encounter two distinct packages: