The main booster pieces are hollow cast resin, with crisp molding and engraved panel line details. One of my strap-on boosters has some warpage that will need to be reformed under hot water: make sure you check your pieces before assembly. There are a few minor molding gunges that will need sanding and/or filling. All parts are still attached to their pour plugs. The copper tube forms the main core piece that the strapons will cover up in the final assembly. The styrene strip is to be glued to the copper tube to represent the sustainer's cable tray. The cross braces at the base of the rocket are not provided and will have to be fashioned by the modeler. The instructions include detailed steps on forming the main sustainer with the copper tube and resin top and bottom sections, with special attention given to make sure the parts line up, along with attaching the strapons to the sustainer section. Most of the instructions are in English text, with explanatory diagrams used as needed. The instructions also include several other detail drawings, an overall diagram of the rocket that serves as a painting guide, and a short program history.