This diffuser can be used with or without essential oils to purify and scent the air. It is whisper quiet due to ultrasonic technology. Depending on your choice of essential oils, diffusing can help to keep you focused and attentive for work, or calm and relaxed at the end of a working day. It has a light changing function, moving through 7 different colours. This can be turned off if desired. It is easy to use and has four convenient timer options, allowing you to set the unit to run for 1,3 or 6 hours. If left on, it will automatically shut down when the water has gone. You can also choose a comfortable mist output mode (strong or weak). It acts as an air freshener to neutralise unpleasant odours from cooking or pets. It's 400ml water tank allows you to diffuse for 6 hours. Comes with a 1 year guarantee.