Fiber disc material:aluminum oxide Diameter:100mm,115mm,125mm,150mm,180mm,230mm Grit:40#~400# best quality Fiber discmaterial:aluminum oxideDiameter ... :40#~400# Characters: The fiber discs have high surface removal rate, long service life and optimum surface finishing. They are ... metal, NF metals, wood, plastic, marble and cast iron. Use these discs, even the most difficult surface can be worked ...