Ideal For Everyone: This Rathburn Ring Stretcher is ideal for both beginners as well as expert jewelers to increase the size of a ring. Notes: (1) Not to be used for stone-set rings. (2) Before using you should anneal your ring. (3) Some rings with weak solder joints, and some cast rings (casting causes metal to be more porous) can break when stretched. (4) You have to make sure you use ring stretchers with plain ring bands only. (5) A light coat of oil is applied to the stretcher to avoid Oxidation. (6) Do not use Titanium, Tungsten, or Stainless Steel. These metals are delicate and will break. Keep in Mind: Inspect for any solder joints that may break apart when stretching. You may need to anneal to soften the ring to afford the expansion of the metal. Generally, this tool fixture will not expand more than 1 finger size. Specification: Material: Steel Application Type: Ring Enlarging Ring Size Capacity: 6 Or Larger Finger Size Steps on Collet Holder: 7 Overall Length: 6-1/2" with base Weight: 9.59 Ounces (271.88 grams) Product Dimensions: 5.8 x 1.2 x 1.2 inches (14.7 x 3 x 3.3 cm) Package Content: Tapered Pin, Mandrel with Nylon Base.