Aluminum oxide paper is clog resistant and self sharpening for longer life. Loop backed sandpaper firmly attaches to the foam disc, preventing debris from collecting behind the sandpaper, and eliminating a major cause of streaking. 100 grit sanding disc for radius 360 sanding tool. 8.75" aluminum oxide paper is clog resistant and self sharpening for longer life. Loop backed sandpaper firmly attaches to the foam disc preventing debris from collecting behind the sandpaper.