Named simply 2SJ226, this 84.5 KB PDF refers to a JIS-registered P-channel FET and most likely contains the part datasheet, even though it sits in the schematic section. Expect specifications such as drain-source voltage, drain current, on-resistance or transfer data and a package outline. A technician uses it to identify leads with a meter, confirm the device is a P-channel type and select a suitable substitute. Since the file name says nothing about the maker or case style, verify those against the actual part.
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.