Yankee Candle Sleep Diffuser and Refills create a relaxing atmosphere for a great sleep. Mess-free refill bottles make using the Sleep Diffuser a dream! Simply insert the refill directly into the diffuser - there s no water to add - and enjoy 30 nights of relaxing fragrance*. Set the diffuser s timer for two, four, or eight hours of soothing ambience, at the fragrance intensity you find the most restful. *Based on 8 hours of nightly use on lowest intensity setting Top: Bergamot, Cardamom, Heliotrope. Mid: Jasmine, Neroli, Tuberose, Ylang, Labdanum. Base: Benzoin, Tonka Bean, Sandalwood, Musk. Top note is the initial impression of the fragrance, middle note is the main body of the scent and base is its final impression.