7 Honeycomb Pattern Higher Diamond Concentration More long Lsting 3.2mm Thick Polishing Pad for concrete granite marble engineer stone. Remind: Please NEVER use high speed grinder polisher with rubber backer (Rubber Backer’s max velocity / capacity is 5000RPM). 25 Pieces of 7 Inch. D iamond Polishing Pad for granite concrete marble engineered stone and 2 pieces of 7″ Rubber Backer/Pad Holder (5/8″-11 female thread arbor). 5 X Grit 50 100. 4 X Grit 200 400. 1 X Grit 10000. 2 Pcs of 7″ Rubber Backer (5/8″-11 female thread arbor). 3.2mm thickness. Recommend 3500 – 5000 rpm. Wet or dry use (wet use recommended).