Ultrasonic LED Night Bulb Air Humidifier Price in Bangladesh. This ultrasonic LED night bulb-shaped air humidifier is designed to add moisture to the home. It contains a reservoir of water that diffuses into the mist and filters moisture from the air. It can increase humidity to help ease skin or sinus problems. This bulb-shaped humidifier can change color when used at night. It has a 500mA operating current and 5V DC input voltage. And, it can be run for up to 6 hours.