RAR archive of 6.95 MB whose name gives only DWR-M920, a D-Link 4G LTE router model, without stating what the package contains. It is likely firmware or service material for that router, but the contents should be inspected before use. When using firmware for recovery, check the hardware revision and region on the device label, since D-Link builds are revision-specific. Keep a dump of the existing flash where possible so the original configuration and calibration data can be restored if the new image fails.
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 @fileservicelaptop. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.