Thermacell Powered Mosquito Repellent Refills create a 15' zone of protection against mosquitoes. These cartridges are compatible with fuel-powered Thermacell Repellers, Lanterns, and Torches. Long-Lasting Defense â Each repellent mat lasts up to 4 hours and each fuel cartridge lasts up to 12 hoursRepel Mosquitoes in Air, Not on your Skin â Repel mosquitoes without DEET sprays or lotions on your skin. Scent-free, no smoke, no flames, people-friendly, and pet-friendly. Proprietary Formula â Independently tested and EPA reviewed for safety and effectiveness. Repels tough mosquitoes, including those that may transmit Encephalitis, West Nile Virus, and Zika Virus. Includes â Ten 12-hour fuel cartridges and thirty 4-hour repellent mats. NOTE: For Outdoor Use Only Each mat lasts up to 4 hours and each fuel cartridge lasts up to 12 hours Scent-free, no smoke, no flames, and people-friendly Includes ten 12-hour fuel cartridges and thirty 4-hour repellent mats | Original Mosquito Repellent Refills, 120 Hours