The 7-Zip plugin adds support for 7-Zip archives. You can pack files and directories into 7-Zip archives; browse, test, and unpack 7-Zip archives; and delete files and directories from 7-Zip archives. Files in 7-Zip archives can be encrypted.
See the Archiver and Menu Extension sections in Using Plugins for a description of basic operations with the plugin archiver and menu extension.