Covering the 2SC3775 NPN transistor, this 125 KB PDF belongs to a run of JIS-numbered 2SC part documents filed under schematics. Its contents should be datasheet data: absolute maximum ratings, electrical characteristics and the package outline. The name gives no board or device context. Use it to verify pinout before in-circuit measurement and to choose a substitute with matching or higher voltage, current and dissipation ratings. Read the full marking, including any rank suffix, on the part being replaced.
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.