Remind: The backer and router bit’s arbor is 5/8-11 Female Thread. VERY IMPORTANT REMIND: Velcro Backer’s max velocity / capacity is 5000RPM. Please don’t use it with high speed grinder/polisher. This package carries (a)-(c). (a) 1 Piece of V40 (40mm / 1 1/2″ Full Bullnose) Router Bit/Profile for 40mm Thick or High stone concrete travertine (5/8″-11 Female Thread arbor). (b) 1 Piece of 4 Diamond Ultra Wide Segment Turbo Row Grinding Cup Wheel. 5/8-11 Female Thread arbor. (c) 27 Pieces of 4 Diamond Polishing Pad for granite marble concrete. 5 X Grit 50 100 200 400. 2 X Grit 800 1500 30 00. 1 X Grit 6000. And 1 Piece of 4″ Velcro Backer/Pad Holder (5/8″-11 Female Thread arbor). Please don’t use with high speed grinder/polisher. With water feed hole, can be wet use.