There is no clip that directly attaches to the rear of a 7520; the BlackBerry is designed to slip into a holster.

An advantage of the holster is that it contains a tiny magnet that automatically turns off the Blackberry's screen whenever it's inside the holster. (All the software continues to run, such as Verichat though) ... This saves some battery power.

The holster magnet is also useful for automatically displaying incoming emails. If you pull the BlackBerry out of the holster within 20 seconds of an email alert (i.e. vibrate), the email automatically displays on the screen in a pager-style manner.

There are many replacement holsters if you don't like the hard-plastic holster that is included with the 7520.