Our essential oil diffuser feature 550ml capacity, even in strong mist mode still work for 9-10 hours, and weak mist runs for 12-14 hours, works well disseminating the aroma steam to your room. You can use this as an aroma diffuser and personal humidifier, ideal for apartments, office, studio, child’s room. This is real, rather than other brands claims 300ml capacity run for 10 hours.(VAPOR AMOUNT: 55ml/h VS 30ml/h)