The file name gives nothing beyond 2SC3460, a Japanese JIS designation in which the 2SC prefix denotes an NPN bipolar transistor. Although filed under schematics, a 113 KB PDF like this is typically the device datasheet. It serves to check pinout, voltage and current limits and the outline drawing when replacing a failed transistor in a power supply or amplifier stage. Open it with any PDF viewer, and remember the part itself is commonly stamped C3460 without the leading 2S.
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.