While they all mean the same type of LCD display, the "F" in FSTN can stand for "film compensated," "formulated," or "filtered" (with STN standing for "super-twisted nematic" which GEI also makes). A layer of film is placed between the display and the rear polarizer to provide better contrast and a sharper overall display.
GEI LCD manufactures a complete line of FSTN solutions with custom designs welcome and extremely cost-effective. For more information or a quote, please visit our Contact page.