ロジャー スミス 5 It's a huge upgrade from a small Iris Oyama purifier I have been using. The filter media is much thicker and fan is larger. I like the auto feature which adjusts fan speed based on pollution levels though at times it whirrs rapidly for seemingly no reason and then goes back to normal moments later. Filters are expensive in Japan. In auto mode it's quiet and barely noisier than my laptop fan.