Arovast via Amazon offers the Levoit 100ml Color-Changing Aromatherapy Essential Oil Diffuser in White for $15.99. Coupon code "RNYZIRK5" cuts the price to $9.99. Plus, Prime members get free shipping. That's $20 off and the lowest price we could find. It features a 7-color LED light and auto-shutoff. Deal ends August 13.