Combined data document for the BD135, BD137 and BD139 transistors, filed under schematics, 51.0 KB in PDF form. The sheet typically gives package dimensions, terminal identification, maximum ratings and gain figures for all three members, which differ chiefly in voltage capability. A repair technician would open it in any PDF reader to check pin order before soldering, compare ratings when substituting one variant for another, or match a complementary pair. Always confirm the full marking on the failed device, since gain grade suffixes can matter in biased stages.
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.