The RAR format allows a single large file (like a game or high-quality video) to be "split" across multiple smaller archives.
The "Th030" naming convention suggests this archive contains assets or data related to: Th030.part2.rar
You cannot open "part 2" in isolation. You must have Part 1 to begin the extraction process; Part 2 is automatically pulled in by the extraction software once the first part is processed. 🌸 Contextual Link: Touhou Project (Th) The RAR format allows a single large file
RAR archives often include redundant "Recovery Records". If part 2 becomes slightly corrupted, the software can use these records to repair the data without requiring a re-download. Th030.part2.rar