The 2SK2108 is the part number behind this 93 KB PDF, which is indexed as a schematic but most likely holds the transistor datasheet. The 2SK prefix is the Japanese JIS registration for N-channel field-effect transistors. The name does not say who made it. Read the sheet for absolute maximum ratings, electrical characteristics and the package drawing. Match the marking on the original component and choose a substitute with equal or better voltage and current figures.
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.