Small RAR archive labelled for Apple model A1990, the 15-inch MacBook Pro with Touch Bar, referencing T2, the Apple security chip on that machine. The name does not say what is inside, so expect firmware or related files such as a BIOS or bridge dump and inspect the contents before use. Work on T2 Macs is restrictive, as the chip controls boot security and SSD encryption. Back up any original chip data, check the logic board number on your board and verify image sizes before writing anything.
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 @hrtechno. 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.