What is this? And how do I get another one?

[BentGear]

I have looked through the Haynes manual and rock auto and other internet searches to determine what this pulley wheel is called. Mine has a groove in it, that is wearing a groove in the belt. I think the hose clamp was rubbing it sometime in the past. Anyway, can anyone tell me what is called and know where I can find a new one? 

[The86manche]

Its an idler pulley

[Kaiserman]

What he said. Any auto part store should have one. Single bolt through the center holds it on.

[cruiser54]

They're common as belly buttons.