These tarts are great! They come in a wide variety of scents and work with a simple Tart Warmer. The tart warmer can either be electric (plug it in and flip the switch) or have a unscented tea light burning below the tart to warm it. I use an electric warmer. It is safe and easy because it has no flame- yet I can still have the awesome Yankee Candle scents that i LOVE. The warmers also come in a variety of designs. I also love that the tarts are less than $2 each- It means that I can change scents whenever I want without wasting an entire candle. The tarts and warmers are available online or at the Yankee Candle store. The package says that they last for 8 hours, but in my experience they last much longer than that. I would recommend this system to anyone, who wants all the scents and ambiance of a scented candle, without the flame!