Our expanding ring mandrels for ring making are made with wear-resistant alloy. While other materials such as wood or carbon steel rust or wear down, these ring expanders will withstand the test of time even with heavy use. Heavy duty annular tensioner and reducer combination. No need to hold it with your hands. The heavy-duty base allows you to maintain stability while enlarging your ring. You can easily change any size and fit comfortably in seconds. It's effortless to use this expanding mandrel. There is extra room on each ring size to accommodate tape to keep the inside of your rings scratch-free. For proper function, apply a layer or two of tape to the step you will be using. This helps protect the inside of your ring. Tha zinc alloy ring size adjuster about 2.36 inch(6cm) in diameter, 6.89 inch(17.5cm) high.Expanding mandrel offers a high level of precision when making rings. The ring adjuster is suitable for most rings, both men's and women's rings, and also suitable for all kinds of materials and styles of rings. Colour:As Shown Material:Metal Package Contents: 1 * ring stretcher Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.