Made of HEPA filter paper, the purification efficiency up to 99%, so that the release of healthier air Easy to remove and replace as part of the routine maintenance. Filters maintain the cleaning performance of the DYSON DC19 DC20 DC21 DC29 while reducing the infiltration of dust, pollen and other allergens into the air you breathe. To keep your vacuum running at peak performance, please replace your filter every 2-3 months. Package Contents: 1 HEPA Filter for Pre-Motor Filter washable Dyson DC19 DC20 DC21 DC29; 1 X Pre-filter for dyson dc19 dc20 dc21 dc29 How to clean the filter: 1. Remove the tray by pressing the tray release button 2. Open the bin door to empty the bin 3. Now press and lift the filtered or release tab 4. Remove the filter by grasping the yellow tab 5. Cleanroom filtered by tapping against your trashcan 6. To reinstall the filter, press the lever of the metal filter, with the side of the filter and push the filter down, the filter door will not close if the filter