The case has a small metal nubbin on the back that slides into the plastic belt clip. I've gone on record several times
against what I believe is the "Bat-belting" of America.
I refuse to wear my PDA, Pager, Phone, BlackBerry device, wallet, and Insulin Pump on my belt. I don't want to wear a belt to keep my pants up, only to then weigh it down with a bunch of techno-crap. Whew.
That said, I tried out the clip in the privacy of my own home, and also found it to be of high quality. The clip is of similar ilk to the ones that you can get for Nokia mobile phones. You keep the clip on your belt all the time, and with a push button you can quick-release the PDA. You can do this with one hand, using your thumb to press the button while pulling the PDA away. It works fairly well.
There's a bit of aiming involved to putting the case back on the clip. It doesn't slide down like the cell phone clip, but rather you come at it from the side. After you've gotten used to it, it's no trouble. Of course, you can also just life up the velcro flap and pull out your Visor. It's a very secure clip, and while I wouldn't recommend it for handstands, it easily withstood me running up and down the stairs. The last thing I need is to hear my Visor going down the stairs by itself. If you are a Visor user who digs the whole belt thing, you'll be pleased.
As you can see in the side by side picture, it's not a very form fitting case. It's more of a PDA "catch all." The case worked well for my Visor Deluxe, my Prism, and my Windows CE Casio E-105. I may have stretch it slightly when I put in the E-105, but generally any average-sized PDA will do fine.
The Copilot-20 works fine with Visors with smaller Springboards like the EyeModule which only sticks out a half inch. It doesn't fit the Visor when the Minstrel "S" Wireless Modem is inserted however.