Clinically proven to reduce dust mite population & reduces the effect of allergies Reduces asthma & allergy symptoms Interferes with the dust mite feeding & breeding cycles thus reducing allergens produced Mains powered with an effective coverage up to a cubic volume of 62m Totally safe to pets & humans The Aller DMC Dust Mite Controller is a clinically proven product. The device works by emitting a range of ultrasonic sounds not heard by humans or pets when plugged in. These sounds interfere with the feeding & reproductive cycles of the dust mite reducing allergens produced & over a period cause the population of mites to decrease. Patient trials show a reduction of symptoms just after a few weeks of use. Symptoms caused by dust mite allergens often include Asthma wheezing or a tight chest eczema & other skin conditions sneezing or a runny nose bronchitis coughing & nasal congestion.