The Dust Mite Controller, produced by good ideas smarter living, is a plug-in device that uses ultrasound waves to help control dust mites. The repellent sound generated by the device is undetectable to both humans and pets. It is designed to be used indoors and operates electrically once plugged into any mains socket. This discrete white coloured device is useful in reducing dust mite infestations, with a range of 62 square metres. It has been clinically proven to reduce asthma and allergy symptoms and the discomfort they cause. This item is used and has some minor discolouration around the on light but is in excellent working condition.