What is "mosquito coil"

n. A mosquito-repelling incense, usually shaped into a spiral, and typically made from a dried paste of pyrethrum powder.

A mosquito coil is a mosquito repelling incense, usually shaped into a spiral, and typically made from a 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 nettings to allow continuous smoldering. Burning usually begins at the outer end of the spiral and progresses slowly toward the centre of the spiral, producing a mosquito-repellent smoke. A typical mosquito coil can measure around 15 cm in diameter and lasts around 7-12 hours. Mosquito coils are widely used in Asia, Africa, South America and Australia.