Starflex Surface Conditioning Disc, 4-1/2" for use on 4-1/2" angle grinders, set of 2, Purple: Extra Coarse Grit Ideal for surface conditioning & cleaning, removal of rust, paint, weld spatter, etc Extra heavy duty grit for car frame cleaning, etc Quickly cleans and conditions uneven surfaces, follows difficult part profiles Silicon carbide abrasive, thick, strong, extra coarse grit