Data sheet for the BC640 PNP transistor, with the file name noting ratings of minus 80 V and minus 500 mA, catalogued as a schematic and stored as an 88.9 KB PDF. It should contain pinout, package outline and full electrical characteristics including gain and saturation figures. Technicians consult it when replacing a failed small-signal or driver transistor, checking lead orientation, or judging whether an alternative PNP part meets the voltage and current requirements. Note that small TO-92 devices from different makers may use different pin orders, so check carefully.
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.