4" 100MM Diamond Dry Flexible Polishing PadsMost wet granite polishing pads are designed to operate on machines with a maximum of 4,500 RPMs. Dry pads should operate at 2,500 to 3,000 RPMs. In the case of marble, the optimum polish should occur between 2,000 and 2,500 RPMs.Item No.DiameterThicknessGritDP-A380mm / 3"2.1mm50#, 100#, 200#, 400#, 800#, 1500#, 3000#, white buff, black buffDP-A4100mm/ 4"2.1mm50#, 100#, 200#, 400#, 800#, 1500#, 3000#, white buff, black buffDP-A5125mm / 5"2.1mm50#, 100#, 200#, 400#, 800#, 1500#, 3000#, white buff, black buff