ZIP named for the ZyXEL P-650R-T1 v3 ADSL router, only 224 bytes in size, so it cannot contain an actual firmware image. Most likely it holds a text note or link and works as a placeholder. A full firmware package for the v3 hardware revision is needed for recovery or upgrade. When you have one, confirm the revision printed on the router label, upload the image through the web interface or recovery mode, and avoid any power loss while the flash is being written.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @biosarchive. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →