Boardview in .brd format for the Apple MacBook Pro Retina 13 inch, model A1502, logic board 820-4924-A. At 576 KB it contains component outlines, reference designators and nets for the whole logic board. Repairers use it alongside the schematic to locate power rails, measure diode-mode values at test points and find the culprit on a board that will not take charge. Apple 820-xxxx numbers are silkscreened on the logic board, and the suffix letter marks the revision, so check both. OpenBoardView, FlexBV and similar tools read Apple BRD files.
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 @boardviews. Enginerys does not host this file.
How to open a .brd file
The most common boardview extension. Several unrelated formats share it, which is why one viewer opens a .brd and another refuses it.