New BenchMate Inside Ring Mandrel Graving Tool. This is a new BenchMate inside ring graving tool. The inside ring holder is great for many wide, delicate or unusual rings that are difficult to hold with an outside ring clamp. This attachment adds inside ring-holding capability to any BenchMate. It gives 200% more access to the outside of the ring and keeps it from flexing while you work. Channel, bead and bezel settings are surprisingly easy using this inside holder. From the set of collets, you select the closest size that fits inside the ring. The screw expands the collet to hold the ring securely. These hard plastic collets won't scratch or mark rings. With an extra collet set, you can double stack collets for extremely wide rings or hold several rings simultaneously for high volume work. You receive: 7 Collets. Expansion Screw. Wrench.