06:16 Oct 21, 2011 

Caroline, you need to consider the expression '½ cup' as a whole; it means the kind of hinges that instead of having a round part that lets into the door, they have just a half-round shape (though I don't know why that's supposed to be better, since you still have to cut a round hole for them!)

I don't actually know why they specifically state '½ cup', as I think most of them these days are; perhaps it is to differentiate them from earlier types, which were perhaps 'full cup'?