The way it works is it sends the sound of you guitar through a tube that you hole in your mouth. Then you can go waa or ooooooooooaaaaaaaaaaaaa or what ever. The old ones you'd have to hang the tube next to a mic, but the Dano has built in mics, although they suck and feedback a lot if you're too loud.
Yeah Very true and they wont let you send it back either! I bought it when it first came out for $130 now I see its in MF for $99. Its a cool stage gimick, loose the supplied mics cause they feed back way too much. I just ran the tube up to my mic stand and wire tied in to my SM-58, now the sound goes in to the SM-58 instead of the little ones it came with. Same difference except the sound comes out of the main PA speakers instead of my guitar amp now! It takes alot of practice to get used to it, and alot of people think that you actually talk into it but you dont, you just use your mouth to make the shape of the word you want to emulate and the sound coming out of the tube bounces off the inside of your mouth and comes out past your lips and the mic pics up the sound! pretty cool! One draw back is thats its a 9v eater so either get a adapter for it or stock up on batteries! I use it very little on stage just for (sweet emotion and livin on a prayer) and it works pretty good (don't spill beer on it!!).
For a 100 bucks ya cant go wrong!