To "produce" or extract the original content from this file, you generally need to follow these steps:

The numbers "1245 - 1391" likely refer to a specific range (such as page numbers, episodes, or years), but without more context, it is impossible to know exactly what the "piece" inside contains.

Do you have of the archive downloaded in the same location?

: Right-click on part1.rar and select "Extract Here" or "Extract to [Folder Name]." The software will automatically detect and combine all subsequent parts to recreate the original file.

: You must have all corresponding parts in the same folder (e.g., part1.rar , part2.rar , part3.rar ). If any part is missing, the extraction will fail.