Without more context on where you encountered this file, it is difficult to provide a specific list of internal "features." If you are looking for details on its contents, you can safely inspect it using the 7z l wo_sample3.7z command in a terminal to list the files without extracting them.
: It could be a specific attachment from a technical tutorial, a bug report, or a private data transfer. wo_sample3.7z
: It may be a specific sample file used to test the performance of 7-Zip compression algorithms or data recovery software. Without more context on where you encountered this