The file is a compressed archive containing a specific digital product, likely an ASMR or audio work , from the Japanese digital marketplace DLsite . The "RJ" prefix is the standard product ID format for that platform.
When downloading files with an "RJ" prefix from third-party sources:
You can search the ID "RJ140155" directly on DLsite.com to find the original product page, which will list the creator, cast, and description of the audio work.
The original, free, and open-source software for this format.
The 7z format is popular for digital media (like high-quality audio files) because it offers several advantages over standard .zip files:
It uses the LZMA algorithm, which can make files significantly smaller than ZIP without losing any data quality.