OX Tools Diamond Cup Grinding Wheel OX PCTB 4 4 Inch (Turbo Segmented 7 8 Arbor Concrete Leveling Masonry Coating Abrasive Angle Grinder Disc) Annular Cutters 000 RPM Maximum Speed Rating: 000 RPM Maximum Speed Rating: Precision balanced dual flute cutter body runs vibration free in high speed handheld routers Side Mounted Cutting Blades: Removable alloy steel side blades slice through heavy earth Wet or Dry Formulation: Hardened metallurgical matrix bond chemistry operates reliably under water flushed suppression or continuous dry cutting lines keep the grinder chassis flat to prevent the cup rim edges from digging sharp trenches into the aggregate face