Piccolo Ultrasonic USB DiffuserA portable therapeutic diffuser for home, office, or travel. Continuous operation for up to 8 hours. 100 ml (~3. 5 oz.) water capacity. Coverage up to 100 ft. Rotating or constant color or candlelight options. Details This sleek little diffuser is a great way to disperse your desired essential oil or blend! An ultrasonic transducer transforms water and essential oils into a cool mist that preserves the oils' health benefits and humidifies the room.