Rathburn Ring Stretcher For Resizing Rings. This is a new Rathburn ring stretcher. It can quickly enlarge plain bands. Simply tapping the end spreads the outer mandrel and stretches the ring. This is used for wedding bands size 8 and larger. To reduce rust in storage, metal tools received may come in packing grease or oil. To remove packing grease we recommend using degreaser and a rag. FindingKing works hard to update our descriptions and pictures of our merchandise. As part of a process of ongoing innovation by our suppliers, newer versions of the item shown may be shipped before we are able to complete an update. As a result there may be a slight variation in color and design.