General description This replacement rubber brush set is designed for various models in the 800 series, including 850, 860, 861, 864, 866, 870, 871, 880, 890, and 900 series such as 960, 970, and 980 robotics. It is recommended to replace the brush every 2 months to maintain optimal performance of your vacuum cleaner. Technical specifications Color: Gray Material: Plastic Package Contents: 4 pairs of roller brushes Measurement allowed error: +/- 1-3 cm