Stadea Series Standard K - 4" Diamond polishing pads Wet Dry set with rigid rubber backing pad for concrete countertop flat and edge polishing, concrete floor polishing, Granite polishing, Quartz Polishing, Glass polishing, terrazzo polishing, travertine polishing. Set of 7 polishing pads size 4", one pad each for grit 50, 100, 200, 400, 800, 1500, 3000 and one piece rigid rubber backing pad with 5/8" 11 thread. Never run over 5000 rpms for safe usage and optimal performance.