Fluval Impeller Brush Set. As part of Fluval's complete line of cleaning accessories, the Impeller Brush Set is ideal for keeping your filter motor working at peak performance. Key Features : Effective motor cleaning for maintaining maximum filter performance Cleans impellers, impeller covers, wells and shafts Great for hard-to reach areas and detailed cleaning Included : 2 Brushes: 1 x 3 1/2" (8.5 cm) L x 1/2" (1.25 cm) diameter 1 x 3 1/2" (8.5 cm) L x 1/4" (0.6 cm) diameter