These step jaws are designed primarily to grip in the contracting mode; the base (foot) of footed bowls. The step sizes provide optimum gripping for three foot sizes with minimal crush damaged wood. There is also an expanding dovetail made for alternative recess gripping of bowls. Can hold bowls up to 12inch in diameter. Optimum Step sizes: *42mm (1.65inch) * 50mm (2inch) * 64mm (2.5inch)