Optimus U-31002 1.5-Gallon Cool Mist Ultrasonic Humidifier for $22.61. Shipping is free on orders over $49. If needed, use this Filler Tool to pad the order for free shipping. Here is a screenshot for reference. It features a water empty automatic shut off switch and refill light, adjustable mist volume control, and 1.11-gallon tank capacity.