OK, so i want to buy this toy to my nephews in the US... i have no idea what is it and where to find it

Did anyone knows what i'm talking about and maybe where can i buy it?
It's supposed to be a big thing in the US now, it's kind of a spinning toy for kids... looks like this:

www.beyblade.com/beyblades/beybladesandaccessories/5/beyblades

thanks!
Alex