RAR file of 382 KB named for the H87M-PLUS, a micro-ATX desktop motherboard on the Intel H87 platform. The name lists no revision or content details, so extract it first to identify what is inside, most likely boardview or schematic material given its size. Such documentation is used to trace the standby and main power rails, find the components around the VRM and Super I/O, and locate a shorted capacitor quickly. Confirm that the board revision printed on the PCB corresponds to the file before measuring.
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 @boardview. 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.