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.