"The Aroma Stream is a compact and quiet unit for diffusing the pure fragrances of essential oils in the air in complete safety - there is no naked flame or heat involved, just a stream of stream of cool air. It is safe to leave unattended or while you sleep. Its features include two fan settings and low power consumption. Add your choice of pure essential oils to the cartridge supplied, insert into the base of the unit, plug in and switch on. W 135mm x H 165mm x L 165mm"