Krachtig en meerlaags filter voor 3-voudige reiniging van lucht: filter voor grof stof, filter H13 en actieve koolfilterDo you know the way silent a whisper is? Whispering produces a seem stress of approx. 30 dB(A). That is actually louder than our Aerostyle units at the lowest setting. And usually you wouldn’t sit right close to them.Anti-topple