Citronella oil is a natureal oil that has been used effectively to repel mosquitoes for many years. By incorporating the oil in candle wax, a pleasant smell, a source of light and a mosquito repellent is produced when lit. With the wax being placed in a tin, there is no loss due to running, all the wax is used. Ideal for camping and indoor use. Each candle will burn for approximately 16 hours.