8mm BURNISHING RIVETING WHEEL MARGIN ROLLER POROSITY REMOVER WITH HAMMERING BALL BEARINGS MADE IN GERMANY Riveting wheels/Margin Rollers are used to burnish or to remove porosity, cavities, marks, pits, scratches or any other imperfections from inside the rings, bracelets, or any other items where these wheels can fit. Works best on Gold, Silver, or Platinum without metal loss. These riveting wheels should be used in rotary handpiece at relatively high speeds with light pressure applied to the surface of the metal. There are 3 sizes - Small, Medium, and Large with head of the riveting wheel/margin roller contains an appropriate number of bearings/hammers thus enabling it to remove various imperfections, as follows: Small - Head Diameter: 080 - 8mm - 6 Bearings Riveting Wheels/Margin Rollers are mounted on 3/32"/2.54mm shanks. Caution: Allow the individual roller bearings on the head of the wheel to do the work by applying light pressure to the surface while moving it back and forth across working area. Too much pressure can damage the tool as well as cause an injury. until results are achieved. Continue moving it back and forth until the desired results are achieved. Made in Germany by prestigious quality dental and jewelry tools manufacturer.