Infuse your home to an inviting, continuous fragrance. Just insert the fragrance refill into one of our decorative Yankee Candle? ScentPlug Fragrance Diffuser, plug it in, and you'll enjoy room-filling fragrance for up to 30 days each. Refills are sold as twin packs - a convenient way to make sure you always have a reserve on hand so you never run out. To use, simply remove the refill's cap and slide the bottle into the ScentPlug Base until it snaps into place. Rotate the base's plug to match your outlet, keeping the ScentPlug Fragrance Refill upright. When the oil disappears, it's time to replace. Bases sold separately. Fragrance Notes:Top: Ozone, Leafy Greens, BergamotMid: Lily Of The Valley, RoseBase: Vetiver, Cedar, Musk, Woody NotesTop note is the initial impression of the fragrance, middle note is the main body of the scent and base is its final impression.