8119 4in MK Convex Wet Polishing Discs by MK Convex Wet Polishing Discs Convex, Hook & Loop backed discs. Disc backs are color-coded for easy grit size identification. Max 3,700 RPM. Set includes one disc of each grit. . Posted in Polishing & Profiling Equipment, Polishing Pads, Buffing Compounds, & Backer Pads, Tile & Stone Tools