Flexible, abrasive coated foam sheets. Flexible foam pad enable users to sand hard to reach areas such as headlight openings, around door handles, door jambs, etc. Helps to eliminate finger marks and can be used wet or dry. 4-1/2 x 5-1/2 Superfine. 20 sponges per box Superfine ranges from grade 500 to 600. 3M Softback Sanding Sponges are coated with aluminum oxide mineral. Each grade uses a range of mineral sizes.