Stops Explorer from hiding extensions on 'known file types', which is the well-known phishing vector (innocent.pdf.exe → innocent.pdf).
MaxTweaks applies this tweak with one click and snapshots your original setting first, so you can revert it cleanly at any time. A System Restore point is offered before batch changes, and every tweak links to its official source.
Get MaxTweaksOfficial documentation: https://learn.microsoft.com/en-us/windows/win32/shell/folder-options