Yeah....that's the "multi clamp". This dude named "Ike" over at Thunder's Place turned me on to those things about a year ago when I was searching for something to use as a Uli Device.
They are dirt cheap. I got mine online, from a website called www.not-just-parts.com ... do a search for "multiclamp" when you get there. They cost $2.95. If ya just get one, with shipping it comes to about 7 or 8 bucks, so if you can find them at a store near you it's a really good deal considering how great this thing works for girth exercises.
It takes some getting used to operating the little dial on top, but after a few times of using it you can get it on/off in a flash.
I wouldn't advise cutting it like in the pics that Cap put up, unless you're wearing it for "stealth" but there's still a chance you could fuck it up. But even so, they are only 3 bucks so who cares?
Godsz- The only reason I suggest trimming it down is that the extra gets in the way. Considering how very little of the clamp one uses for X-Ulis no harm can come from clipping the excess. Plus, like you said - for the price who cares if you fugg it up. Get another one. Hell, get one for your mailman.
Fellas- This thing takes a bit longer in the "on and off" department than the Cable Clamp, but the subtlety of the incremental tightening is from Penis Enlargement heaven. Check out GodSize's link but don't forget about Wal-Fart, I happened across it completely by accident while shoplifting one day. Anyone check places like Pep Boys?
And yes: ALL props go to Ike for the discovery. Good guy is Ike. I like Ike. I like to be like Ike.