RAR archive of 3.36 MB whose name points to Memtune for the RX4xx series, most likely a memory timing tool for AMD Radeon RX 400 series graphics cards. The name gives no version number or list of included files, so inspect the contents after extracting. Utilities of this kind change VRAM timings and are often used alongside VBIOS editing or mining tweaks. Save the card's original VBIOS before applying changes, because wrong memory settings can cause artifacts, instability or a card that no longer starts.
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 @videocard_notebook_resistance. 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.