This is a CD This is the Overhaul manual for the GTSIO-520 Continental aircraft engines.
if its in a piper, mooney, cessna, beechcraft, bellanca etc. you need this manual on a CD These manuals are non current and are sold for educational reference purposes only.
Please check my store for more piper , cessna and beechcraft manuals .Continental GTSIO-520, continental service manual, continental engine factory overhaul manual