cup brush with twisted knotted wire used for polishing Diameter:50, 65, 75, 100, 125, 150, 200mmMaterial: ST: Knotted steel wire :0.35, 0.5, 0.8mm BS: brass coated steel wire crimp: 0.35, 0.5mm SS: stainless steel wire: 0.35, 0.5mm cup brush with twist knotted wire