Claire Mabel Goldsm via Amazon offers the Ceenwes 500ml Essential Oil Diffuser for $21.98. Coupon code "7TD8YUWF" cuts it to $14.95. Plus, Prime members bag free shipping. That's tied with last week's mention, $7 off, and the lowest price we could find. It features up to 10 hours of continuous use, a timer, auto shutoff, and seven changing mood lights. Deal ends January 26.