At 464 KB, this PDF for the 2SC5264 is the largest of the related transistor files and is likely a full datasheet with characteristic curves. It sits in the schematic category, though the 2SC prefix under the JIS scheme identifies an NPN bipolar transistor. A technician uses it to confirm terminal order, case type, ratings and gain behaviour before replacing a failed device. An LS-suffixed variant is catalogued separately, so match the full marking on the board part before relying on these figures.
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.