The NanoProtect HEPA filter cleans faster than H13 (4). NanoProtect HEPA filter's low-resistance fibres maximise the airflow. They are subjected to rigorous life and durability tests for continuous operation 24/7.
I bought the philips nano protect air purifier
It's very good and has helped us a lot as we suffer from asthma and other allergic reactions to dust Pollen ect, it really works well for us all and has helped so much indoors. This filter does amazing at collecting everything as it passes through to clean the fresh air that comes out into our home.