PDF of 155 KB covering the 2SA1707 transistor, with nothing else stated in the name. Even though it sits in the schematic category, the content is likely a datasheet, since 2SA under the JIS system indicates a PNP bipolar transistor. Typical sections include absolute maximum ratings, DC and AC characteristics and a mechanical outline. Technicians rely on such sheets to identify leads, confirm a component is within specification after testing, and select an equivalent PNP device with matching polarity and adequate ratings.
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.