The OPOWO ultrasonic humidifier features 3 levels of spray adjustment with a maximum spray height of 31.5 inches, covering up to 484 sq. Ft. Of space. The humidifier's 5.5-liter water tank lasts up to 55 hours, saving you from the hassle of frequent refills and giving you more time to do the things you love. The aromatherapy air humidifier has a built-in 2ml essential oil bottle that you can add your favorite scent to, it will create a relaxing natural scent in your home that helps calm the mind. The OPOWO cool mist humidifier's top fill design lets you enjoy one-step filling and the wide opening lets you clean the tank easily.