Filter filters fine dust to reduce dust, pollen and other from penetrating into the air you breathe It is suggested that it should be replaced every 2-3 months. Replacing the accessories regularly will also improve the cleaning performance and suction of your sweeping robot,Also can help to provide you with air and healthy living environment Applicable models: For M7 Pro M8 Pro Robot Vacuum Type: Vacuum Cleaner Parts Dust Bag: Replacement Accessories Parts Material:Non-woven fabric + plastic colour:White+black Package Contents: 15 * dust bag 10 * filter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.