for direct works on copper, zinc, plastics : delicates tone and shadows. Allows the same kind of gray shades as abrasive mines (look here) , with soft shadows. The flexibility of the materials soften gradations. Unlike super abrasive mines, is not a substitute for the scraper. 3 grits available, the two larger make two shades of gray, the finer very slightly soften the first ones. 6mm diameter and 22mm lenght If your are looking for thinner rubberized abrasives, 2 others handles are available, for 3mm abrasives and for 2mm abrasives.