Candle warmers, hot plate-like devices that melt candles without an open flame, are becoming very popular. The most basic candle warmers resemble a coffee mug warmer and are little more than a hot plate that plugs in. They heat the candles from the bottom up but apply no heat to the sides of the candle jar. This means it may take some time for the scent to be released from the candle. They are less expensive than other models and if all you want is a slight fragrance in the air these basic candle warmers may just do the trick. More advanced candle warmers actually allow the candle to sit inside them. Resembling a mini deep fryer, these candle warmers are 6.5 inches tall and have a 4.25 inch wide opening to fit any standard sized jar candle. Because these warmers engulf the entire jar scent is released from warming both the sides and bottom of the candle. Scent is released quicker with this method.