PDF of 45.8 KB titled 2sa2017, the JIS part number of a PNP bipolar transistor, as indicated by the 2SA prefix. Expect a datasheet with absolute maximum ratings, electrical characteristics and package dimensions, though the name says nothing about the maker or variant and the file is catalogued under schematics. On the bench such a sheet tells you which leg is which for meter testing and whether an equivalent part with the same polarity, ratings and footprint is suitable.
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.