The parts are intended to replace the F-1 engines and first stage thrust structure/heat shield parts in the Airfix or Monogram 1/144 scale Saturn V kits. The engines have the batted insulation molded in place, while the thrust structure part provides more accurate detail. The heat shield has finely raised panel lines and insulation detail molded in place. Some cleanup will be required around the edges of the part. The engines are hollow and need to have their pour plugs removed. They also have some flash that will need cleaning up at the openings of the nozzles. There are also some very minor airholes in some of the engines that will need filling.