Features: Nickel-plated diamonds. These high-speed diamond cutting discs can be used with your rotary tool to cut a wide variety of materials. For cutting wood, glass, plastic, metal, marble, masonry, stone, concrete, and fiberglass. For use in tight spaces and for straight cutting. Material: Nickel-plated steel. Shank size: 38 mm. Disc diameter: 50 mm. Maximum speed: 20,000 rpm. Note: Please add water for coolant when using the diamond tools. Package weight: 41 g. Package dimensions (L x W x H): 50 x 50 x 20 mm. Contents: 10 diamond cutting discs of 50 mm + 2 connecting rods.