I found this video to be helpful in seeing how this works.

http://www.viddler.com/explore/michimammut/videos/11/

this has no moving parts, and is essentially a single piece. much lighter than the grigri, but functions slightly differently. kind of like a cross between a reverso and a grigri. it's a very cool piece of gear.

It's not the same as the Grigri (see the answers to the other question) but it is lighter and a lot cheaper. Check out the other answers on this page.

Great device, like a grigri but not. Bottom line is that this device is not for newbies. Works like a charm when you've belayed for a while but the average newbie would have trouble. The wrong combination of moves means a friction-free fall that me lead to some burned hands from rope grabbing if there isn't any quick thinking involved.

i have one of those devices. I always like things that are light, and really simple. Grigris are great for lots of things too. I like the Smart a lot because it's a single piece, and super light. I find it feeds great, locks off on all sizes basically the same as a Grigri.

I found a belay device review in climbing, but it did not include the Smart device. I am curious to know if Angus is comparing the feeding to old-style or new-style Gri-gri belaying. The old Gri-gri belay style where people hold in the braking device does make feeding easy but is patently unsafe.

I would have to say I disagree with Angus. It feeds 100x better than a grigri. If you want to get a feel for how easily it feeds just clip a rope with a locker and that is how smoothly it feeds. I have used one to leadbelay and I have to say that I am very impresed and I intend on buying one sometime in the future.

This is a re-incarnation of an older petzl device. I cant remember the name, but it is now discontinued. It never worked all that great. It looked cool and got lots of great reviews, but in the end function is whats important.

I haven't used it that much, but it's a bit tricky. It doesn't feed quite as easily as say a Grigri, but it's better for bringing up a second on a multipitch route. Check out the latest issue of Climbing Magazine, they've got a detailed review.