Bulk packaged 5pc 3/8 x 1 1/4 inch medium grit cartridge sanding rolls. Most are of what we would call a medium grit, but they could vary. Cartridge sanding rolls are rolled up sandpaper with a hole in the middle. As the sandpaper gets used, there is more below. Use with 1/8 inch cartridge sanding roll mandrel, not included. For use with Dremel Rotary Tools.