Compact 47.8 KB RAR file carrying the project code 08530 with an sb suffix and nothing else describing the device. The code style corresponds to Wistron, an ODM whose boards appear in many branded laptops, Dell in particular. Its contents are not stated, though the size points toward a small firmware image suitable for chip reprogramming. Extract and inspect it, make sure the PCB marking matches 08530, save the existing chip data with your programmer, and check that the image length fits the flash device.
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 @schematicslaptop. 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.