Size: 3mm. Polishing wheels are 2.5cm in diameter, grinding wheels are 25mm in diameter. They fit your hand drill, drill press and tool and with a 3mm collet. Practical, made of high quality scouring pad, sturdy and practical. Good polishing effect, high efficiency, low cost. 4 types with 80 grit (brown), 150 grit (green), 240 grit (red), 300 grit (black). 20 pieces per grit, 80 pieces in total. Wide application: 80 pieces are quite enough for daily use, suitable for your polishing needs, and are used for polishing all kinds of metals as well as jewelry and non-metallic materials in small areas for deburring rust and polishing the surface. Special conditions apply to international products, they are sold from abroad and may differ from local products, especially in the fit, age rating and language of the product, labeling or instructions.