Smooth and shape flat or curved surfaces with our convenient 4.5" x 5.5" sanding sponges. Suitable for all metal types including platinum, these sponges can be applied wet or dry and can be folded or trimmed to fit into tight areas. Made of durable foam rubber that has been permanently bonded with aluminum oxide abrasive. This 5pc assortment contains one each of the following grits: 100, 180, 220, 280 and 400.