Oak Leaf via Amazon offers the Oak Leaf 1.3-Liter LED Cool Mist Room Humidifier / Ultrasonic Essential Oil Diffuser for $24.99. Coupon code "MNKWUUCM" drops that to $16.99. Plus, Prime members bag free shipping. That's the lowest price we could find by $5. It diffuses essential oils and tap water in a steady 360° swirling mist and lights up in seven different colors.