I don't see why it shouldn't. It says it will.
At a guess, I'd say it's a Linux server that Zyxel has written a front end for and that you access via a browser on your local computer. That's a common way to access software on servers, to avoid the command line. For example, commercial grade software does it all the time; webmin and phpmyadmin being just two examples.
Providing the front end works as advertised, it is indeed a bargain. You'd pay almost that price currently for the 2TB hard drive.
My instinct would be to say, if that's what you want, snap it up.