PIC Mosquito Repelling Coils have been a dependable insect control product since 1953 when they were first sold to drive-in theaters. The PIC Mosquito Coil with Terra Cotta Burner Mosquito Repellent contains 4 coils and one terra cotta burner. The burner mosquito repellent helps repel mosquitoes in confined areas outdoors. Each mosquito repellent coil will burn for up to 5-7 hours in total. The terra cotta burner has a built-in metal stand for easy use. These mosquito control coils are perfect for patios and porches - just set them outdoors every 10 ft. for best results. The removable lid can be left on or off the burner to control the amount of air exposed to the burning coil. Do not use indoors and see the packaging for additional instructions for proper use.