8 hours protection against disturbances from aedes mosquitoes A mosquito coil is a mosquito-repelling incense, usually made into a spiral, and typically made using dried paste of pyrethrum powder. The coil is usually held at the center of the spiral, suspending it in the air, or wedged by two pieces of fireproof netting to allow continuous smoldering. Burning usually begins at the outer end of the spiral and progresses slowly toward the center of the spiral, producing a mosquito-repellent smoke. A typical mosquito coil measures around 15 centimetres (6 in) in diameter and lasts around 7–12 hours. Mosquito coils are widely used in Asia, Africa, South America, Canada and Australia.