The .7z extension indicates the file was created using 7-Zip , an open-source high-compression utility.
It is a standard practice for fansub groups or community archivers to group episodes in batches of 10. For instance, archives with this exact name have been linked to series like Medabots and other classic animations shared in high-quality formats.
In some public tender systems, such as the Lithuanian CVP IS , archives are often split into ranges like "1-30.7z" and "31-40.7z" to organize supplemental technical documents. Technical Characteristics
The name sometimes appears in technical repositories or support forums as a timestamped or sequenced backup.
It may represent a specific sequence of project additions or a backup of a system state captured at a specific time (e.g., a file named with a timestamp ending in 31-40.7z ).