Shop for Heating, Venting & Cooling at The Home Depot. Re-hydrate your surroundings with Keystone's KSTHW50LAG 1.3 gal. Warm Mist Humidifier. Perfect for those who suffer from sinus problems, Keystone's warm mist humidifier has two mist intensity settings, high and low, putting you in control. The high setting releases 1.7 cups of warm moisture per hour and will run continuously for up to 10.5 hours. The low setting releases 0.8 cups of warm moisture per hour and will run continuously for up to 21 hours. Keystone's warm mist humidifier will not only help you to breathe easier but the refill indicator, auto shut-off and tip-over switch will give you peace of mind as well. Color: Blacks.