As the other reviews have stated, these nuts are shaped perfectly. When I lead with my friends' racks, their stoppers always seem to take extra fiddling to get around irregularities in the crack. The scalloping, the curve, the rounded edges--these nuts place fast, clean easily, and are simply the best I've ever used. They've even arrested a fall or two, which isn't surprising, but definitely inspires confidence. I've also got the Peenuts, which supplement these bad boys perfectly--and are invaluable for pin scars. DMM makes the best nuts--period.