DUO ACOUSTIC Low noise emission technology motor. Integrated noise reduction system.INTELLIGENT MODULE WITH LED Convenient maintenance indicator with LED and integrated instructions and soft start/stop functionality for increased durability of the motor.HYBRID FILTRATION May be used with or without a filtration bag. When used with a Duovac disposable filtration bag, it performs a double-filtration for unparallelled air quality.MACHINE WASHABLE ANTIBACTERIAL PERMANENT FILTER SILPURE is a new generation of antibacterial treatment that stops the growth of bacteria and prevents the spreading of germs that cause odours on the permanent filter. The SILPURE treatment is natural, nontoxic and ecological.