Dico 541-784-4 Nyalox Wheel Brush 4-Inch Blue 240 Grit 4" diameter blue brush had 240 grit abrasive nylon bristles Safer to use than wire brushes Doesn't shred bristles, maintains its shape Lasts far longer than wire brushes 1/4" hex shank mandrel for use in all drills Last up to (10) times longer that Wire Brushes Convenient Shapes and Sizes for all jobs Gray-Extra CoarseOrange-Coarse and Blue-Fine Will not rust & maintains its shape. Safer to use. For light cleaning and polishing of woods and metals