Using this outer filter is easy. First, turn off your Rapido handheld vacuum and unplug it for safety. Then, open the filter compartment of your vacuum cleaner. Remove the old outer filter carefully. Place the new filter (Part No. 4055291415) in the same position as the old one and make sure it fits snugly. Close the filter compartment. When using your vacuum, don't overfill the dust container as it can put extra strain on the filter. For maintenance, check the filter regularly. If it looks dirty, you can gently tap it to remove large debris. It's recommended to replace the filter every few months depending on how often you use your vacuum. Always store the filter in a dry place when not in use.