OWENOJO  This is a shocking, sloppy piece of junk.

As many others here have said, it is useless. It cant even correctly open its own file format! Back in olden times, stuffit expander and its related formats, sit, bin , hqx and the dreaded sea thingie, were the standard mac archive formats. Now that many files are zipped, os x deals with these no problem, this thing is only needed to do one thing: open its one native format: a format you only encounter when a) someone made the mistake of encoding a file with this monstrosity, and b) to open old archives/ obsolete software you downloaded. IT CANT EVEN DO THIS RIGHT. version 12, 11, all cant extract a .sit properly without showing zero files, or missing files. How can Smith Micro/Alume/Aladdin (ive lost track!) market this evil, vile bastard offspring off years gone by anymore?

Get the free "the unarchiver". it works.  
(Version 12.0.1)