Specification: There are 50 pcs sanding bands sleeves, with 5 mandrels. They are used for polishing. Special electric grinding polishing sand ring, and often used for metal rust removal, wood, polishing. Sandpaper Circle Diameter: 12.7MM/0.5" Mandrel's dia: 3.2MM/0.125" Grits: 40 Function: for polishing Usage: Set in electric mill metal grinding head Installation Method: Put the sandpaper on the rubber pole, with a screwdriver gently rotating the screw and the rubber will expand so that the sandpaper can be fixed on the pole. Package Included: 50x Sandpaper circle 5x Mandrels.