FEATURES Made from high-grade corundum powder and premium diamond and carbon steel sand, with a smooth, nickel-plated coating for long-lasting use Fast, easy, and smooth drilling of holes; increases drilling speed for a clean, precise, and smooth cut without chipped edges in just a few seconds Ideal for drilling into extremely hard materials such as marble, slate, glass, tiles, stone, and many more. The material only requires water for lubrication.DO NOT DRILL WITHOUT WATER! These drills can be used with a standard drill machine, perfect for clean and precise holes and provide both excellent performance and a long lifespan. PROPERTIES MaterialSteel Weight205 g Diameter8/10/12/14/16/18/20/22/25/50 mm UsageGlass / Ceramic / Tiles / Marble / Stone... DELIVERY CONTENT 1 SET (10 pieces)Diamond Drills NOTES Please continuously add water while drilling to keep the drill cool. Use a speed of less than 800-1000 revolutions per minute. Due to differences between monitors and lighting conditions, the actual color of the product may differ slightly from the color shown in the pictures.