Documentation for the 2SD2170 transistor, provided as a 54.0 KB PDF and indexed in the schematic category. Japanese JIS part numbers beginning with 2SD identify NPN bipolar transistors for low-frequency duty, so expect a datasheet with characteristics tables and package drawings. The file name states nothing beyond the part number. A technician would use it to confirm pinout, collector-emitter voltage and current ratings, and to evaluate equivalents when the exact part cannot be sourced.
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.