Great for working with all metals, including platinum, sponge sanding pads from 3M are flexible enough to conform to almost any contour or surface. Micron-graded abrasives make them safe for every stage of sanding and pre-polishing. Use wet or dry for a wide variety of metal, model-making and lapidary applications. Made of long-lasting, closed-cell foam rubber bonded with aluminum oxide abrasives. Convenient, hand-sized pads can be folded or trimmed to fit into detailed areas. Micro-fine grade.