Contains four replacement butane cartridges and 12 replacement insect repellent mats for use with for use with all Thermacell products. Each mat provides 4 hours of repellency. Each butane cartridge lasts for up to 12 hours. Hang packaged. Thermacell products can NOT be shipped Air or International. Thermacell products repel mosquitos which may carry the Zika Virus, West Nile, Chikungunya, Dengue fever, and other mosquito-borne illnesses.