DURABLE: This diamond-coated polishing set has a 3mm (1/8") shank and includes 18 x diamond points, 5 x mini diamond wheels and 2 x 3mm (1/8") mandrels. VERSATILE: Suitable for a 3.2mm collet and a maximum 18, 000 RPM, it is ideal for deburring, etching, polishing, smoothing, cutting and grinding glass, metals, ceramics and plastics.