The Sonus SFX-1 4" Spot Pad is the ideal solution for polishing out surface scratches, water or bird spot etching and heavy swirl marks when using a Porter Cable 7424 dual-action machine. Larger pads simply cannot apply enough energy to the polish to effectively "cut" the paint to make the repair. The The Sonus SFX-1 4" Spot Pad focuses the dual-action machine's energy on a smaller area to get more work out of the polish. Use with Sonus Restore (SFX-1) or other compounds and paint cleaners designed to remove 1200 grit sanding marks. When used in conjunction with the proper backing plate, the Sonus SFX-1 4" Spot Pad can be used with a dual-action polisher, rotary buffer or cordless drill. The Sonus SFX-1 4" Spot Pad is an excellent solution for buffing clear plastic headlight lenses, too. Use in conjunction with your favorite plastic polish and a cordless drill motor to remove scratches and light clouding caused by UV exposure. Sonus