... Because you have to regularly clean the filter / ventilation system (2 foams, one above the other in the rear) of the vacuum cleaner to operate silently. If there is too much dust in the filters, it will have to suck harder and therefore make more noise (we lose the nation SILENCE goes with the unit). Aside from that, it is perfect for relatively light and compact, actually rather quiet compared to a "conventional" said vacuum while maintaining efficient suction power, the supplied accessories are practical, well placed and the cleaning of the tank is in 2Mn to break everything (disassembly / drain / wash as necessary / reassembly).