- The classic model from Nilfisk. *The Viper DSU12 is one of the symbols of Nilfisk quality and reflects elegance, good performance and many years of efficient cleaning. *Sturdy durable construction. *High suction power 880Watt. *Very good filtration. *Low noise level 65dB. *Boiler capacity of 12 liters. *Power 880W. *Cable length 10m. *Weight 5.6kg. *Dimensions 39x38x48cm. *The VIPER DSU series of vacuum cleaners is ideal for the daily cleaning of offices, hotel rooms, restaurants and shops. Suitable for medium-duty use.