smart wifi wireless essential oil aromatherapy 400ml ultrasonic diffuser & humidifier with alexa & google home phone app & voice control - create schedules - led & timer settings sierra modern home a smarter diffuser - the sierra modern home diffuser is a great addition to your smart home that is powered intelligently and wifi compatible. simply download the companion app to control features like led color, mist intensity, timer settings, scheduling and more directly from your phone. our smart diffuser is also alexa compatible and can be used with echo/tap/dot to control simply by using your voice. a large 400ml water tank allows for up to 12 hours of continuous mist.