PDF datasheet named SM5K3-5, roughly 234 KB, which appears to cover a range of related SM5K parts from 3 to 5, though the name alone does not confirm the exact scope. Opening it in a standard PDF reader gives the pin descriptions, electrical characteristics and typical connection diagrams. It is handy when one document describes several family members, but read the ordering or marking table carefully so the values you use match the specific variant fitted on the board under repair.
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 @datasheet_technar_org. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.