According to the service condition, it is recommended to replace the filter every 3-6 months. Clean filters maintain best suction levels. Dirty filters restrict airflow and greatly reduce suction. [Applicable models] For 166521562156a, powerforce 16651613056. Made of high-quality materials to vacuum safety and always in working condition. The filter assembly is installed inside the dirt tank to select the vacuum of the carbon canister. The filter can be cleaned. Rinse with warm water and mild detergent. Make sure that the filter is completely dry before returning to the machine. The filter keeps the robot clean while reducing the penetration of dust, pollen and other into the air you breathe.