Along with Dysons patented Root 7 Cyclone technology, the DC20 Allergen has a HEPA filter and Bactisafe screen which traps and kills bacteria and mould on contact, making it a boon for allergy sufferers. Vacuuming the floor is thorough as well, thanks to the Dyson Contact Head, which keeps the closest contact with all floor surfaces, even as you pull backwards. Storing the DC20 is neat too, since the hose and wand compress and wrap around the unit for easier putting away. And its also good for cleaning the car with as you can attach tools directly to the end of the hose. The Dyson DC20 has also been awarded the British Allergy Foundation Seal of Approval.Dyson vacuum cleaners offer a free a 5-year warranty. To take up the offer, complete the application form you'll find in the box.