Mandrel Polish Bristle Brush 60 Tools fits Dremel 12 Stiff brushes that each measure approximately 1/4" (6.5 mm) in diameter 12 Soft brushes that each measure approximately 1/4" (6.5 mm) in diameter 12 Stiff brushes that each measure approximately 3/8" (9.5 mm) in diameter 12 Soft brushes that each measure approximately 3/8" (9.5 mm) in diameter 12 Stiff brushes that each measure approximately 1/2" (13 mm) in diameter