Named simply 50SQ, the 132 KB PDF in the schematic category covers what looks like a component family rather than a specific device; no brand, model or board is given. It is likely a series datasheet listing several voltage grades, closely matching the 50SQ060 file in size. Use it in a PDF viewer to find pinout, package dimensions and electrical limits. Because a family sheet groups multiple variants, identify the full code printed on your component before selecting the right row of specifications.
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 @cyberlanelectonik. 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.