A:Answer All of the Blue pure 411 machines are great options for smaller rooms and all use our patented HEPASilent technology. The Blue Pure 411 and 411+ are both manual machines with a single button to move the levels of your air purifier on, up, and off. Like the 211+ machine, the 411+ utilizes a solid white metal case to hold its filter in place, allowing you to use the machine without a washable pre-filter. The Blue Pure 411 AUTO has a single sensor that will sense the air quality in your home and has the ability to run in auto mode. All three machines use the same 411 particle and carbon filter and will assist in cleaning out particles, gases, and odors in your space.
