The Heaven Fresh HF707 Digital Ultrasonic Humidifier Silver is a compact, stylishly designed humidifier and purifier, which is ideal for smaller spaces. The negative ions option makes it a dual purpose humidifier as well as an ionic air purifier. The HF707 features a blue night light, Hi/Low speed settings, built in timer, low water indicator and one touch controls for easy use. Mist Evaporation Rate: Low: 50ml/hr (1.7 fl oz), Med: 200ml/hr (6.8 fl oz), High: 300ml/hr (10.1 fl oz). Negative Ion Output: 3,000,000/cm? (49,161,000/inch?).