2 Pack, Emery Impregnated Disc, Ideal For General Polishing Of Most Ferrous Metals, Stones, Glass & Ceramics, Use It To Remove Small Burrs & Scratch Marks Left By Grinding & Sanding, Ideal To Clean & Define Grooves, Emery Impregnated Disc Is Ideal For Cleaning & Polishing Coarse Surfaces, Use Mandrel #402.