Krachtig en meerlaags filter voor 3-voudige reiniging van lucht: filter voor grof stof, filter H13 en actieve koolfilterDo you know how peaceful a whisper is? Whispering makes a sound tension of approx. thirty dB(A). That is actually louder than our Aerostyle products at the lowest environment. And frequently you wouldn’t sit ideal close to them.