1. Ceramic stone grinding wheels with three different hardnesses are made of green silicon carbide or high-purity white corundum plus alumina. Harder than brown corundum. It has good cutting performance, low heat generation, abrasive grains, and good thermal conductivity. It can be used for cutting tools and other high-hardness materials. 2. The cotton polishing wheel is made of high-quality cotton and has high toughness. Two different hardnesses are available for polishing hard and soft materials, adding smoothness and brightness to your products. The flocked wool polishing wheel and fiber wheel have super adhesion, high-quality environmentally friendly materials, and remarkable mirror polishing effect. 3. Use: Bench grinder polishing wheels are used for polishing, waxing, cleaning and repairing items. Mainly used for polishing jewelry, plastics, wood, glass, soft metals, and derusting non-ferrous metals such as brass, stainless steel, and aluminum. This set can meet your different working needs. Suitable for general small bench grinders, bench buffers and hand drills. Name:Electric drill base grinder Please note:the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:Black Material:Metal Package Contents: 1 * Drill Holder 5 * grinding wheels 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.