Help your child drift off to dreamland with the Vicks 3-in -1 SleepyTime Ultrasonic Humidifier a cool-mist humidifier essential oil diffuser and color-changing night-light in one. The SleepyTime humidifier helps you create a personalized calming environment for your child to rest. Soothe a cough or stuffy nose with the humidifier s added moisture and provide the comforting scent of Vicks anytime by adding Vicks VapoPads. The Vicks SleepyTime 3-in-1 (VUL500) does not require a filter and runs up to 24 hours per filling.