Buy some for your friends they'll love you. Only 8 bucks. Looked cool, so I bought it. Works great, easiest I ever changed a tire. Can't wait to try it on my road bike.
Knobs tend to hang the lever up when seating the tire.
Of course I flat 30 minutes into my first ride. I highly reccomend this item. Cost might be a bit high if it breaks. We're talking difficult 700x20 road tires here. She didn't have a problem.