... )/ T27(flat ) Flap disc/ flap wheel/ abrasives disc/abrasives polishing disc /mop disc/1. Diameter: 4'',5'',6'', 7''2. Grain: 40#-320 ... SANDING PAPER , NORTON SANDING PAPER , DOMESTIC SANDING PAPER6. Backing support : SBS PLASTIC BACKING ,FIBERGLASS PACKING iTIS GOOD FOR CLEANING OF WELDING SEAMS ...