The Vicks Starry Night Cool Moisture Humidifier provides soothing, cool, invisible moisture and a calming environment to help your child sleep. The V3700 features a projector screen that transforms you child’s room into a starry night sky. Its scent pad heater produces soothing menthol vapors for added comfort. Automatic moisture balance system. Easy to Use: Variable humidity control for customized output, Runs up to 24hrs per filling on low, Perfect for Medium to Large rooms. Water is absorbed into a porous wicking filter. Air blowing from the fan through the filter evaporates moisture into the air.