As far as I remember, Berninas have two. A basic foot, about the same price as other feet, that just turns the fabric strip as you sew. The other one is a whole different ball game and cost over £100 sterling, and even then I would need to buy a separate shank that is extra. It takes the fabric strip and folds it both sides of what you want to bind, then the one row of stitching is supposed to sew both sides together whilst wrapping them around your work. Nice gadget, not so nice price, and I don't think it did any width other than the standard 1/4inch that commercial bias for dress making is.
But then I really like doing the binding on my quilts.