To optimize burn time, and achieve close to 15 hours of burning, you must burn a votive candle in a glass, (or other material), votive holder. These are premium quality candles and clean burning. They are made of paraffin wax, with a textured outer finish. There are 20 votive candles per box. Votive Candles should Always be burned in a votive candle holder, to contain the melting wax that Provides Fuel to the Flame, or they will drip where you probably don't want candle drippings.