The 3-IN-1 Ultrasonic Diffuser is a humidifier, air-purifier and night light all in one. Using ultrasonic technology, the 3-IN-1 diffuser allows you to experience Essential Oils in their purest form without heat, chemicals or toxins. Place the diffuser on a flat surface and insert power cord into wall socket. Remove the cover from the base. Fill the water tank to the maximum water level line (200ml) with cool tap water. Do not fill water beyond the max level mark in the water tank. Add 6-9 drops in total of your favourite pure essential oil. Replace cover and secure lightly. Press the Mist button to turn on your diffuser. Press the LED button to turn on light for ambience.