2 Blue Rubber Polishing Wheels With Mandrel. This a new set of 2 blue rubber polishing wheels with mandrel. Blue rubber polishing wheels can be used to polish all precious except gold. They can be used with a Dremel tool. Each wheel measures approximately 7/8" (22 mm) in diameter. The mandrel has a 1/8" (3 mm) shank. We work 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.